The Russians made things cheap and dirty. They did not concern themselves with esthetics-which is why their capsules look like they were built in haste.
Plus, in space, who needs streamlined fairings? A sphere with stuff attached to it works just as well.
Green strong! Strong like tractor!
Which is it?
FWIW, Sputnik was made from scratch. Explorer was made out of spare parts.
To address the question of the o.p., the driving impetus for the difference in designs is multi-faceted, but it has to do less with cost or landing mode, and more with launch vehicle limits, spacecraft on-orbit layout, maturity of manned space vehicle technology, and reentry speed. The Vostok was a very primitive spacecraft, even compared to the contemporary Mercury capsule, and while the navigation and avionics control system on Mercury could be only slightly favorably compared to a series of kitchen timers linked together, the system on Vostok was basically a wind-up toy. As thus, its capability to actively control reentry orientation was non-existent, and the G forces prohibited positive pilot control during reentry flight; it relied on buoyancy–an imbalance of weight that placed the center of pressure (CP) behind the center of gravity (CG) for stability. The capsule was also of a very conservative design, especially the thermal protection system (heat shield) due to the limited state of high temperature material design and testing.
Vostok was also very weight sensitive; it weighed twice as much as a Mercury capsule and even more than the two-man Gemini spacecraft. As such, the use of a spherical capsule maximized interior space for the amount of surface area, and thus, mass. Admittedly, Vostok had a fully on-orbit propulsion system and a fairly impressive instrumentation module, whereas Mercury was basically a boilerplate can with a solid propellant retro motor cluster. Voskhod, the followon program to Vostok, was the first multi-person capsule (a three-man crew capability) that made good use of this ability. Gemini, in comparison, was very light weight, but had less overall mission capability (as it was designed as an interim program to develop and test technology and methods specifically to support the Apollo lunar program), although several follow-on proposals for Gemini included expanding its mission capability and capsule size, including an six- or more-man capsule (“Big Gemini”) to support space station transport and resupply, and even a backup lunar mission vehicle or Apollo rescue efforts.
The differences in the design philosophy and implementation of space launch vehicle designs went far beyond that. Although US and Soviet designs for rockets for space launch applications started from essentially the same point (the German Aggregate family or rockets, of which the A4/V-2 is best known) they diverged fairly radically in basic design principles, based upon the available manufacturing and materials technology, concept of operations through launch flow, prior experience and data, and in no small part the prejudices and preconceptions of the dominant personalities for each development. I could go into more detail, but as the topic of this thread is about spacecraft I’ll demur.
On the topic of spacecraft design, each country stared from essentially a blank sheet, and as anyone who plays around with basic system parameters for rockets and spacecraft will discover, there are many ways to skin that cat. A factor (real or perceived) that dominates the design for one design may not apply to another user. Although intended for a nominal overland final return mode, the Soviet Vostok, Voskhod, and the Soyuz capsules were all designed to survive a “shallow water” landing. (To be specific, the pilot in the Vostok ejected from the capsule during the final phase of re-entry and parachuted separately to the ground, so that a soft landing and capsule survival wasn’t indented.) The Soviets designed for a land-mode landing because they had a large open land area to afford landing and were likely less concerned about the possibility of a capsule landing on some poor farmer’s head. The American space program, on the other hand, needed to use the open space of broad ocean area (BOA) and had a large naval presence to recover the capsule, and so desired a more precise (but difficult to design) blunt-arsed capsule, which was also more efficient in terms of thermal protection.
One of the things that drove the design of the Apollo capsule was sufficient drag such that it would limit the G-forces experienced by crew during a trans-lunar return velocity. For that it needed a large base per mass to allow to losing momentum by gliding. There is no way the Vostok or Voskhod could have survived trans-lunar return without additional ablative aerosurfaces. As has already been noted, the Soyuz 7K-OK capsule deviated from previous Soviet designs by having a bell-shaped reentry module, a spherical orbit (sometimes called “living”) module, and the instrument/equipment module. The spherical habitat provided maximum space while the reentry module minimized the amount of mass returned (and therefore, minimized parasitic heat shield mass that had to be carried into orbit). The function of the Soviet reentry capsule was the same as Apollo; be able to shed additional velocity from a high orbit or trans-lunar trajectory, although Soyuz was not purpose designed for a lunar mission; the Soyuz 7K-L3 and the L1/Zond (Soyuz 7K-L1) Luna program capsules had a lot of weight stripped out to increase its L/D (glide ratio).
Other spacecraft, like the American and Soviet shuttles, converged on very similar solutions to the same problem. (Although the Soviets clearly cribbed from the American design, they performed analysis that indicated this was the optimal configuration for the desired cross range requirements.) The proposed Russian Klipper spacecraft bears a significant resemblance to the X-38 CRV, which is derived from the Martin X-23 and Northrop HL-10, and very similar to the Spiral-derived BOR-4. This isn’t because of spying but convergent design; the dynamics of lifting bodies tends to drive you to a fairly narrow family of configurations. However, in some designs, like the Phoenix/SSX/Delta Clipper Single Stage To Orbit (SSTO), there is no analogue in the Soviet or Russian design history because they never attempted an SSTO design.
So, to summarize, there were technological and maturity limits and design philosophy difference that led to differences in design approach. However, in terms of reentry capsule, both the American and Soviet designs converged on similar (if not identical) solutions of a blunt arsed capsule of conical or bell shaped outer mold line. No spacecraft is designed strictly for looks, although spacecraft designers may have a mental picture of how a spacecraft should look that influences their layout and configuration of the craft.
Stranger
Take a look at the interior of a Vostok capsule: fire suppression system? A fire extinguisher bolted to the wall!
AS for the crew “elimination” system-we won’t go into that!
Stranger On A Train: And that is the most interesting of all.
Ok. Figured there had to be a typically Russian ‘practical’ reason.
Still hideous though. 
And what was the fire suppression system on the Mercury capsule like?
