I don't think how long you've been keeping fish matters much... It's the quality/depth of how you have kept your fish. It also depends whether or not you have been doing it the right way all those years/months. Learning the wrong things young would just make you continue to do things a certain way even if it's not ideal. You could be in the hobby for 20 years, but the only thing you've kept are a bunch of guppies/danios/whatever. Compared to someone 5 years into the hobby but has gone through different kinds of fish, upgraded to bigger tanks, grew live plants, maintained a saltwater tank, and moved from place to place... so in my opinion the years don't matter much.
I do think the age should be included on the user display just to give you a sense of where the advice/opinion is coming from. Not to totally ignore or ruin their credibility, but to factor in whether or not you should listen to a 20 year old vs a 40 year old. I'm not also saying that a 40 year old is necessarily smarter than a 20 year old(fishkeeping wise), but I definitely would not listen to someone that's eight years old...
I do think the age should be included on the user display just to give you a sense of where the advice/opinion is coming from. Not to totally ignore or ruin their credibility, but to factor in whether or not you should listen to a 20 year old vs a 40 year old. I'm not also saying that a 40 year old is necessarily smarter than a 20 year old(fishkeeping wise), but I definitely would not listen to someone that's eight years old...