Computers can be as good as consoles; however the biggest thing that will have to change is the price of computers.
If we assume that the price of games for different formats are similar (I know they aren't, but I will say so for the sake of argument) then the price of the games do not have a bearing on choosing a system. So the only price we have to consider is that of the system to play these games on.
Let us compare a modern console (since the three main ones currently available are fairly equal when all small differences are taken into account)
Take a PS2: it can play DVD's and has very nice controllers. Its games look quite nice (as does the machine itself) for the most part (Tony Hawks underground being a good example). It will course be able to play any game made for it (as will any console) and will play anything straight from the box. It costs about $250 - $300
Now take a PC: It will need a DVD drive (and therefore the software/hardware to make use of this). It needs a control method that is better than the keyboard (yes, it works for some, but controllers are better for many games), and this control method will have to have some form of force feedback since the playstation one is (which is more expensive). The spec of the machine will have to be (at least) a Pentium III with a decent graphics card (32Mb +), and your sound card, box, speakers, mouse, OS, and the monitor (always a big expense). Even if you make the machine yourself, you're going to be looking at $500 or more. And you have to set it up so that it all works as it should (not always so easy)
I am assuming that people are not upgrading, since they still would have had to pay for the doner parts at some point. Also, if you do not have the skill or time to source, purchase and assemble the parts, a new PC which is advertised as a games machine will cost upwards of $500.
So, you have your PS2 and your PC. Of course if you made a basic spec machine then a game like Grand Theft Auto III might cause it some problems to run smoothly. What's that you say, your PC has crashed? My god, has the PS2? umm, of course not (yes it can happen, but it isn't exactly a common thing).
Once PC's can be attained for similar prices as consoles, which have similar working spec.
Note: it is worth pointing out that a PS2 can run rings around an older 600MHz Duron, despite only being a 266MHz processor. Just because the numbers are the same, doesn't mean that the performance is.
feel free to /msg me if you think my prices are off