Isn't Tank Town the small island map, where there is a town in the center of the island, with spawn points radiating towards it? This weekend map in orange was the monster island base, not really TT I don't think. Either way I didn't see it get captured, I was able to play this weekend too.
Anyway, merit for the tactic aside, all sides do it. It is not a mutually exclusive trait of any one chess piece side to capture or not capture.
Plus, if HTC didn't want those bases capture-able, they would be, well, uh, uncapture-able.
