It certainly is, but I think it’s a degree or two less negative. “Is this appropriate? No.” doesn’t have the same “running to teacher” feel as flagging.
Also, if a lot of users have “seen” the post, but not clicked “Yes”, does that say something about the post? What if users who are usually quick to click “Yes” read the post without choosing Yes or No?
Seriously, right? That’s where I’d love to see a trust system be able to determine the difference between an active user who’s trusted enough to post and to make some decisions (this is spam) but not trusted enough to set the tone of the community (their “likes” don’t count as much, their approvals don’t count as much, etc).