It's very true these are public forums and people should be mindful of what they say because others maybe reading it. But at the same time, it does no good to try an point out that someone's comment can be construed as some kind of racist remark. Normal, RATIONAL people will read over things and take it for what it is. It's when someone puts the thought out there, that it's a crude remark, that people stop and rethink the meaning of it.
If you say something is gray, most people will read it that way. But when someone comes in and says, "OH! Gray is mostly black, or gray is mostly white" those previously reading it as gray will stop and think, "HMM... Maybe it is white or maybe it is black." That is when crap starts flying and when I start getting ticked off.
ETA: It's also like the piece of plain white paper with the tiny red dot on it. Most people would look at that paper and never notice the tiny dot. But when someone points it out to them the dot is there, suddenly that is all they can see.
If you were to ever look at my family lineage, you would see a veritable grab bag of races. It makes no difference what each one is. I am who I am and I'll make no apologies for it. And maybe I am just like John Wayne toilet paper... Rough, tough and don't take no shit off no one.