There's a whole lot of people from /r/CringeAnarchy on the way, that's for sure. And having an "even distribution" is an unrealistic expectation to hold, and that's because it's impossible.

But that aside, pretend if this site were exactly as you, individually or among select others, wanted it to be. Would it be correct to assume someone else (or a whole lot of people) might consider it to be an "echo chamber" in some form or fashion?

Absolutely. And thinking otherwise winds up landing with just endless shortcuts and excuses to account for the complexities of communicative society.