Kids and Game time

How much time is too much time in gaming for kids?

I know many parents run into this question in today's world. There are tons of web pages out there talking about this. I myself has asked this question on my Twitter feed this past week and was not shocked on what was said back to me. Seems that people with kids under the age of 10 only give their kids only about 2 hours of screen time for gaming. I myself am in this boat during the warmer days of the year. Since I live in the Northeast we only get about eight good months of warm weather, during the fall and winter I will allow my younger kids about an other hour of screen time but it has to be a creative game, not your point click, or a family game in which they are playing with others.
With reading all these sites and talking to people here is the break down I have gathered.

1 - 3 years old about 30 minutes a day
4 - 7 years old about 1 hour a day
8 - 11 years old about 2 hours a day
12 and older seems to be 2 hours or more depending on school work.

Now you will notice that at 12 I mentioned school work. My older son is now 11 and I do agree that two hours is a good amount, but if he focuses on his school work and gets above grades I don't mind giving him some extra time in game. You all can see that I am a huge believer of hard work should be rewarded. That is why when he does really well at his school work or chores he gets more time. I do a lot of work not only at my job, but on YouTube, Twitch, and here. I might not be the best at all of these, but its trying something new that shows I am working for something new down the road.
This all ties into how much time we let our kids play games, yes games are good to relax and have kids work on different parts of their mind. But too much screen time and its a waste.

How do you all feel about screen time for kids, or even your selfs? Is too much a waste?