Basically what Heparine said. If I deem an offence ban-worthy, I don't see why the user should get back to their old level as if nothing had happened. A ban is _supposed_ to be harsh. Sure, there are cases where I think temporarily being unable to use the site fully without losing the status permanently is an appropriate punishment, but those are minority cases which are handled just fine by the offender dmailing me to show they got the point and me manually restoring their level, and that's by definition a case-by-case thing.
We'd be more than adequately equipped for handling bans if the stupid "only admins can invite users with negative records" restriction was lifted, but even with it in place, the occasional mail to jxh2154 once every two months is not too much of a hurdle, and gives an opportunity for jxh2154 to review the case, which is not a bad thing.
tl;dr: Defaulting to automatically restoring user status post-ban is the wrong policy applied at the wrong level by the wrong person.