tl:dr I don't think gaming is that bad.
This post makes me think of evolution and Coca Cola.
Several thousand companies were formed back when the Coca Cola company was formed but the majority of them selling corset laces and home telegraph delivery and mushrooms and back rubs and breakfast cereal and abortions are not around any more. Coca Cola was addictive and still is so the people who bought it a few times kept buying it. Not every one got addicted to it, but enough people did to keep the sales figures increasing. It became the cultural norm, so much so that carbonated drinks with no useful nutritional content is what people mostly drink instead of buttermilk, or vegetable broth or other possibilities. The chief competitor to carbonated drinks is another addictive beverage, coffee.
Things that are addictive tend to be more successful than things that are not. Being addictive gives you an evolutionary advantage. There are a lot of addictive activities on line -touching base socially with your friends, or searching for information, or getting the sense of productivity that H & H and other games give you. The result is that in this generation a heck of a lot of people are spending a heck of a lot of time focused on something electronic. I'm not saying that this is good or bad. I am saying that if there were a better alternative, that is what people would be doing, instead.
Those discontented guys working at Starbucks in their thirties because they worked at H & H in their twenties? Why are they not working at their careers instead? Yeah, it would be great if they were all working at being entrepreneurs and researchers and getting doctorates and learning to be fantasic computer programmers and so on. But the real world is that most entrepreneurs fail, most people do not come up with good ideas, many doctoral graduates are working in call centers, and there are plentiful unpaid internships being hawked around the local university for people who are being offered the opportunity to write good programs for free. A lot of those guys who are not computer game addicted and are working their tails off to do something ambitious right now are going to end up working at Starbucks in their thirties.
This is probably going to sound silly, but what I have observed about computer gaming is that it is something that people do while they are working on certain types of development that they do not get to make progress at in the real world. I know of a young woman who, struggling as an outsider in high school, got computer addicted to Furcadia and spend endless hours interacting with other players in power struggles, give and take relationships, and learning to create and cooperate with other people. At the time I was deeply concerned with her grades and all her friends murmured that she was wasting her time. However, at the end of that time she had developed a lot of social skills she previously hadn't had. In high school the other people had pretty much squelched her. After training herself to become a leader in her Furcadia world she had learned who to ignore and who to trust, how to motivate other people, how to use their different strengths and abilities and meet their needs. She liked people more and forgave them more easily too.
Yeah, probably in the right rl situation she would have learned more. And maybe the learning took place because she was developmentally ready for it. But the right rl situation did not show up, and on-line gaming was there for her to use those abilities when she needed a place to practice them.
So to me online gaming is like a remedial workshop in isolated skills. The rl world is like being thrown into a baseball game. The on-line world strips away a lot of the details so you can focus on only a certain facet of development. It's like batting practice.
Yes, too much computers is not good for you. Yes, it is better to get a little exercise and talk to real people in person sometimes. Yes, our brains are changing so that we process information differently than we did when kids used to read instead of stare at a screen. But there was a time when people didn't approve of kids reading either. It was just escapism that kept them from productive real life activities. The telephone was another terrible advance that tended to have a bad influence on the young. (Not only were they starting to socialize with other young people every day, but girls were socializing with boys as if there was no deep implication to that change!) No matter how the world changes, people are going to be alarmed with the way people grab new technology and embrace it like it is solving their problems. I think that is because people use the tools at hand to solve their problems.
Anyone who is spending sixteen hours a day in isolation hunched over a computer screen harvesting wheat and feeding silk moths would probably have been spending sixteen hours a day in isolation, if they didn't have the computer screen. But this way they are going to end up with a merchant's cape and their brain is going to be trained toward the habits of perseverence and problem solving and success.