It is funny. I am 27 and I constantly go through the same thoughts as the original poster.
I am a developer for the government here in the UK so my pay is exceptional and I am quite high up too. I know for a fact, that now, I couldn’t move to a game company on a junior salary, as I have a wife and child on the way.
– I don’t particularly like the fact that game companies ask for “shipped 1-3 games”. What difference does it make if you have written C++ for 10 years with IBM, Google, Microsoft, EA or Ubisoft?
I would say I see people find their feet at around 30 - 35. Some people still go out partying and don’t worry about these things at our age, some get down to business like us. The best thing you can do is keep believing you will get there and keeping your project small is the key, especially if your on your own. The second best thing is having people around you who are willing to provide the moral support when your down.
As to the original question - I do not know the answer. I think there are a lot of genuine good games turning up on steam’s gleenlight that have significant influences from our era of gaming. So I would like to think the age is somewhere between 25-35, maybe 40.
I guess in reality age is irrelevant, skills and wisdom are key.