Only Supermods and Mac (and on rare occasions, Admins) can pull the ban switch. Regular mods don't have that kind of authority. If we see a problem, we'll bring it up for discussion among the other mods. Usually one or more of us will intervene on the person's behalf to try to salvage their membership and warn them against unacceptable behavior.
Unless the offense is highly egregious, no one ever suggests banning the person. We talk mostly about how best to resolve the member's issue before it gets too far out of hand.
You'd be surprised how tolerant mods can be and how protective most of us feel toward members. Usually, folks have to try really, really hard to be banned from this site; and when they try hard enough, they are readily accommodated.