Let's not lose sight of the purpose of "banning". It's not to get revenge, and it's not punishment for punishment's sake. It's only a means to an end.
We want to make an accurate, comprehensive and open encyclopedia. We require civility, so it's a nice congenial place to work. We enforce Jimbo & Larry!s NPOV policy, so that we keep bias from creeping in under the guise of "objective fact".
The only reason to pressure or suspend a contributor, is because they sidestep, subvert or openly declare war on our values. If they show willingness to mend their ways, all is (usually) forgiven.
My feelings toward Plautus, Lir, Wik, and Abe (172) are precisely the same: if they will follow our guidelines their help is welcome; if not, we're better off without them. Often after a self-imposed or "mandated" period of time off a user thinks better of rocking the boat and can come on board again.
Don't mistake this is hostility toward people. Think of it as dedication to the mission. We sail the boundless seas together. :-)
Ed Poor Curmudgeonly but softhearted Bureaucrat