Yeah, that's really the biggest issue that makes my head spin, besides the people who say "your" instead of "you're".
I've met so many people who tell me stuff like, "alekhine's defense [or any other] is bad, white gets a big center - why do you play this?" and I have to show them how black slowly dismantles the white center, but they still remain unconvinced of its soundness, because of the simple "white gets center."
And here is the problem - they just stop there. They don't provide lines, they don't provide reasoning. It's like talking to an NPC in a video game sometimes. And more often than not, they aren't able to convert such an "advantage" into a win. And then they say, "oh well I'm not very good, but when you meet good players it won't work on them" - as if understanding the position is a trap like those in the Blackmar-Diemer.
@B1ZMARK - Spot on! The question of the center is "The Great Question" of chess! Activity determines whether the pawn center is a ripe target or a deadly battering ram.
Hypermodern players (and we do still exist) have a better handle on openings which attack and restrain the opponent's pawn center. The situation isn't static, it's dynamic, and those dynamics fundamentally change one's understanding of the opening, and of the center.