If the factory edge lasts longer, someone isn’t sharpening it right. I keep my knives extremely sharp, and I only need to do a real re-sharpening job maybe once a year. Most of the time, a light touch-up with a medium and fine grit stone is all I need to bring back a shaving-sharp edge. With a proper relief bevel your knives will be very, very sharp and stay that way for a long time, unless you abuse your blades.
A factory edge typically has an inadequate relief ground into it. If the resharpener doesn’t properly rebevel the blade to put in a proper relief, then the secondary bevel is more abrupt, has more metal behind it, and thus blunts even faster after a couple of sharpenings. Here’s a brief overview of sharpening, and a much more detailed one that both square pretty well with my own knowledge on the subject.
The sole advantage of an obtuse primary bevel is that the secondary bevel is more robust and resistant to chipping. Of course, that’s usually because it’s blunt as shit. A more robust edge is not something that’s terribly important in a kitchen knife, unless you’re talking about a heavy boning knife or cleaver that will be hacked through tough connective tissue and bone in a way you’d never treat a more delicate blade like a chef’s knife. Or unless you’re sharpening an axe. But even an axe’s edges can be hollow-ground and sharp enough to shave with while still being capable of cutting down a tree without notching. So, really, there’s no reason to “sharpen” your knives like this.
Electric knife sharpeners are universally shitty. They put a very coarse edge on because they use brute force and a coarse abrasive method (usually carbide or tungsten-steel disks) to achieve a quick result. They also destroy the relief — if there was by some miracle any ground in by the factory in the first place — and quickly alter the blade profile because they remove way too much material. This ultimately shortens the overall lifespan of the knife.
With a Western-style through-hardened knife, that’s not quite as critical (though you will chew up enough of the knife to destroy the shape of the blade in a matter of years instead of decades) but with some Japanese Santoku or similar differentially-hardened blades, you could destroy most of the hard edge and be clawing away at the softer material farther back in the blade in a relatively short time.
Steeling is generally only useful for some kinds of carbon steel knives, those with relatively soft (under Rockwell 56–58) blades. Asian-style blades are typically hardened more than traditional Western blades; usually Rockwell 58 or higher. Touch-up honing with a very fine grit stone, or with a ceramic rod is better for these. A traditional steel will coarsen the edge and might rip out sections since the trade-off for hardness is that the edge ends up being a bit more brittle. Most kitchen knives now are some flavor of stainless, which also doesn’t act the same way. They tend to be more brittle than carbon steel at the same hardness, so steeling can actually make the edge blunter by ripping off microscopic bits of the edge instead of returning them to true.
Steeling could technically be done either way. If you do it with the back of the blade up (given a vertical orientation), or toward you (horizontal orientation; not recommended, but I’ve seen quite a few people do it this way) and push the edge along the steel, it makes it easier to judge the angle of the blade to the steel. It’s also much less awkward mechanically considering that blade handles are generally made to be held with the blade facing away from you. If you really wanted to, I’m sure you could steel backwards. You’d probably end up cutting yourself a few times, and you probably wouldn’t be able to address the whole blade — including the tip — and you’d probably screw up the edge angle.
