There is a big difference between the AAA games of today and those of yesterday. The AAA games of today costs sooo much more to make, generally speaking, and that have pushed the budgets for the AA games as well, this in turn have cased a lot of publishers and studios to close because they didn't get their investments back.
The market is bigger today COD sells 20m units every year, GTA V sold 18m their budgets are more than justified. Just because badly run businesses think they can throw the same kind of money at a smilar game and get the same sales doesn't make that a bad thing. Plenty of games are still successful with smaller budgets, and there is more veriaty in the types and sizes of games today than ever before. Bad investments are bad investments, plenty of studios went bankrupt in the past as well. Huge investments that end in massive flops aren't new just look at ET for the Atari an estimated US$125 million total budget across licensing, marketing, development and production including 5 million expensive carts most of which ended up buried in the deasert, now that is something that harmed the industry.