First off folks read reviews (both professional and user reviews) before buying a game unless you absolutely must have that game the day the game comes out.
This will tell you all you need to know within a few days of release if the game is buggy/unfinished/worth playing. Not to mention gives you a better sense of whether it is a game you will like. There are tons of resources out there on the net for this so no need to spend $50 and “hope” the game is ok.
I have personally found games to be much better lately in hitting the streets in a playable manner. Sure they may require some balancing patches and occasionally patches to fix bugs with some particular system setups but most often they are playable right out of the box (not always but usually).
You can also often try a demo of the game before buying. Again not always but often enough.
As for problems downloading and installing a patch almost always these days the developer makes it a fairly automated process. Either from in-game with a button or a check for updates button in the directory the game is installed in. Some are easier than others but even the worst usually are no more than finding your game in a list, downloading the patch and running the patch. The rest just happens and you are good to go. If this is really too cumbersome/difficult for someone then it is a wonder they manage to play any game on their PC or add new software of any sort.
When it comes to needing a $5,000 rig to play games that is rarely the case unless you want to play some modern game at the bleeding edge of graphics on dual monitors at over 1600 dpi with all the eye candy turned on. Most games scale down pretty well to a playable level and still look pretty good. Some few (like Crysis) seem to need a supercomputer to run but they know that and meant to do that. While they want to sell the game they are probably more interested in licensing the CryTek engine that runs the game to other developers and use the game as a showcase of what it can do. In general a computer that was “modern” three years ago should be able to still run most things today but yes, eventually you will get left behind and have to upgrade to play most anything but that is the nature of the beast. In five years your XBox 360 will probably look a little long in the tooth too.
PC games also have the advantage of being able to be electronically distributed. I rarely buy a boxed game from a store anymore and prefer to download them (legally and paid for) via an electronic distribution channel. I know some like the box and such but personally I want the game and do not care overly much about a fancy package or figurine in the box.
And unless you have all missed it console games are getting more pricey. $60 seems to be the norm (for a newly released game) where $50 seems to be the ceiling for PC games (often cheaper…Sins of a Solar Empire can be bought for $45). You are also married to games for that console or you have to buy one of each console. Like a Wii game but have an XBox? Tough. Making the same game for multiple platforms is not easy since each platform has distinctly different hardware and programming requirements.
I am not 100% sure but it is my understanding that while you may sell more units for a gaming console due to more people having them you also pay a substantial fee to the console maker for each game sold (not to mention buy a license to develop for that platform). Anyone can develop for the PC if they are of a mind to and could start doing so totally for free (excepting the cost of their PC).
Finally, PC games frequently allow the user community to develop add-ons/modifications for the game. This can frequently result in some very cool and fun developments to the game. Done with a game after playing through once? Revisit it a few months later to see what gamers have made to add on to it. It can be truly remarkable. Oblivion was widely criticized for numerous shortcomings and the gamer community set to modding it into something really amazing. It can be a bit hard to sort through but it is almost a wholly new experience playing it with some of the more popular mods (looks even better, better combat, improved leveling system, new quests, new abilities…list goes on and on). IIRC XBox is claiming to allow something like this but not so sure how that will work…have to wait and see.
Frankly the PC as a gaming platform has a lot more to offer than consoles and while being a bit more complicated to deal with not unduly so unless you have never dealt with a PC in your life.