Well of course, it's all about the economics.
Better to make small, crappy games, that are more easily made and flip a few coins, than invest time (where time equals money

) to make a proper all rounded up game which probably won't fetch a profit as big as some crappy games would have in the time invested. So every new game (mostly) offers a crappy old lousy play style and super awesome graphics, which is really what gets peoples attention (it glitters...)
Much like the frakking movie industry which is all about the special effects and getting a famous actor, not so much about the storyline...etc
sad, sad times...
