I wouldn't say that personally. While TT isn't as morally grey as many of New Vegas' quests, I disagree that it's clear cut.
Most of the TT residents may be racist, but they are willing to try living with people they hate a lot and Herbert likes ghouls and would welcome them. Roy himself is essentially racist and is willing to blow up Megaton if it hasn't been done so yet. Roy's group also has Bessie, a girl who just wants to have a nice life and misses her younger years. She also has no idea about Roy's plan to kill everyone if you let them in. Killing his group means you're forced to kill her too. So, not counting stuff like kicking people out of TT, you can kill racists who are willing to give folks a chance if convinced or kill some poor ghouls who have a racist leader but are otherwise fine themselves.
From my point of view, there's nothing blatantly good there, mostly dark grey to bad.