Man..
It's really disappointing to see such rampant generalizations about people.

Can't we all just ride bikes? Whether it be for only a few months, or years, or your whole life we're all just rollin' and chillin.
People wouldn't ride if they didn't enjoy it, even if they started because it was the 'in' thing to do. They're still at it, right?
These guys you describe sound like noobs, but there's always noobs in everything and everybody hates 'em, but no one is a noob forever. They'll grow out of it, or grow out of the sport.
They just want to sound like they know what they're talking about and be accepted.
Chill man, you shouldn't let the actions of others upset you like that.
That's p***y s**t man.