What's not to like about taking a bit of time and effort to make the conversions you've put work into making look good and unique look better?
Painting doesn't take THAT long unless you're doing it Golden Demon levels of right, and most people don't obsess over it that far.
Part of the reason you're going to get looked down on (and people will always do so for unpainted miniatures) is because wargaming is partly about awesome, miniature models looking great in a miniature battlefield.
I agree with you about the rules 100%. No miniatures game is so complex that you should forget the rules, and if you're new enough that you might there's no excuse not to have the appropriate codex and rulebook on hand.
But look at it from my perspective. I come to the table with the rules known and my miniatures painted, because that's generally what people expect (unless you say "Hey, I just got this and it's not fully painted yet,"). I expect my opponent to know the rules for his army and to take the time and energy to make his army look decent, just like I have.
You can't spew that bullshit about elitism and then turn around and get pissy about people not knowing every aspect of the rules by heart. That makes you a god-damned hypocrite.