You're statement beautifully self-embarassing. In an ecosystem, if one element of it is unbalanced, it does wreck havock. GTA is not like a lion, but more like a human being that is responsible for wipeing out endless number of other species while destroying our own planet. Or like a Hemlock tree that grows large and toxic, making the soil below unsuitable for other plant life. Should Rockstar not make GTA as good as possible? No, of course not, but that doesn't mean it's not destroying its own environment through excellent evolution.
How exactly is GTA destroying its own environment? In a generation that has lasted almost eight years now there have been exactly two released. And while they have sold extremely well to the tune of millions of copies, there are many, many more gamers who never play GTA.
It's kind of a strange argument, tantamount to saying that there should be no super successful games because they hog all the market. But it's hard to argue that because if there were no GTA (or COD, or WoW, or LoL, or Minecraft, or whatever game you might feel like bellyaching about) you can't know how many of those dollars would just flow to other games. A good many of them wouldn't because those big event titles bring back lapsed gamers and bring in people who were never gamers before or who don't play games other than those. They are the subject of mainstream media stories and get people to think and talk about gaming who otherwise wouldn't. I mean, if Nintendo suddenly ditched Mario, would all of that Mario money just go to Metroid and Fire Emblem?
The problem isn't a few games hogging all the market, but too many games chasing the same dollars. Maybe that sounds like the same thing, but it's a distinction with a difference. It's understandable that every publisher wants to have the next COD. But they try to accomplish this by making something that appeals to the COD audience, which is already well served by a game called Call of Duty. There are more audiences than just males between the ages of 18 and 35, and not every 18-35 male wants to play GTA or COD. So increasingly AAA gaming becomes about winning over that smallish but enthusiastic audience. If you can do it, you'll have a smash success. If not, you'll have a flop. And more and more games become bastardized versions of themselves as Splinter Cell and Dead Space and Dead Rising and Resident Evil and on and on all throw what made them unique under the bus to appeal to that one single audience.
Meanwhile something is happening in the non-AAA space where guys like Jasper Byrne and Jonatan Söderström and Jonathan Blow and Mike Bithell and Vlambeer can all practically (or sometimes literally) work out of their bedrooms and make games that sell hundreds of thousands of copies because they are unique and creative: i.e., everything that AAA gaming isn't anymore. You have new studios cropping up by the day, formed by refugees from Naughty Dog and Rockstar and Ubisoft and Bioware, who are finding success in this space. To believe that everything is bad and the GTAs are eating gaming you'd have to completely ignore this increasingly unavoidable phenomenon of game creators escaping shareholder-driven game development and being successful at it.