Taking about gamers in general, lets consider this; people who grew up playing Atari 2600 are now in their 30s, while people who started with NES are in their 20s. Gamers are getting older. Of course that doesn't mean gaming has to grow up (in fact I'd argue that a lot of people play games to remember what it was like being a kid again) rather I think it has to do with adults having less tolerance for needless complexity and design bullshit than children. When your young you have a lot of time, but very little money. When your an adult you have more disposable income, but less time to enjoy it. A lot of the game companies I mentioned in the beginning really fail to grasp this. They're still doing things the way they did a decade or more ago. Times have changed.
Looking to history it's easy to notice a pattern with the rise and fall of dynasties. Always the end of a line of Chinese Emperors or Egyptian Pharaohs were brought about by natural disasters. In the case of the gaming industry it economic recession, but for all intents and purposes the effect is the same. The big developers mentioned above chose to bunker down and stick to what they knew while companies such as From Software, CD Projekt RED and That Game Company chose to engage in a more flexible approach seizing opportunities where they found them. Unsurprisingly, in the dynamic world of electronic entertainment the latter not the former is the more successful. Sadly, most game companies are still staring at their feet fussing over sales from a purely business perspective. What they should be doing is looking to the horizon where new, exciting and highly profitable gaming experiences can be found.
I've seen this sort of thing happen before with Sierra Entertainment Inc. "Quest" titled adventure games are what brought them to the limelight, but the sequels kept coming and while graphics improved gameplay remained largely stagnant (and in some cases was downright reductive). So, eventually the company perished. The good news is in their final years they had what I like to think of as the "last hurrah!" with titles like Half-Life and Homeworld. Perhaps Capcom is doing the same with Dragon's Dogma? Only time will tell. What is certain though is some of the industry giants mentioned above will not be around much longer. Sad? Hmmm...not sure, but as a gamer I hope that they go out with a bang rather than a whimper.