Speaking for myself, I didn't even post much or try to give advice until I thought I was at least alright. Even when I do I try not to be too harsh about it, and only write stuff I think will actually help. It's a natural thing though, everyone likes to take on the role of the guru or the man when it comes to this, because it makes you feel relatively better about your skills.
As far as internet personnas it might be, just look at 4chan to see that the internet breeds big egos with nothing backing them up. Thing is with this stuff I feel like a fake would be sniffed out quick, its hard to fake this stuff.

Also, I've got a week off soon and I'm thinking of stopping off in a couple of cities to check their scenes out. Where's recommended?