Its simply naive to say that infinite edits means an infinitely good article. If you dont believe that bad, non-vandalism edits take their toll on articles, I invite you to look at the Featured article review. So many articles are ruined by people who simply aren't good at writing prose, and who enjoy adding useless factoids. Articles quite often get worse-- if your idealism has you believing otherwise, please look at this:
http://en.wikipedia.org/w/index.php?title=Hip_hop_music&diff=41510779&am...
This should be a big wakeup call to anyone who thinks that the pure wiki system allows articles to get better indefinitely. Unless we do something about it, wikipedia will simply be a place where articles get great then start to deteriorate. I'm not suggesting stable versions, but surely... something needs to be done.