It's about the principle of the thing, not about content additions/being nice now or anything. Like Space said there's a reason why people get banned, it's because they forget up (whether intentionally or accidentally) and now they need to do the time until they can come back. This is disciplinary action, there's a very logical reason why people are banned and you should not feel sorry for them.
Now what about perma-banned folk? Shouldn't they get a second chance? Well, no. They did something pretty bad to deserve a permaban and so they are simply no longer allowed to post here. Don't pity them, they really did deserve what they got and more often then not no one wants them around anymore either. That's regardless of what amazing addon they have to offer or other great wisdom they have to dump here.
Now if you're a monkeyman of one of those individuals I can understand you think it's unfair and not cool and blah blah blah but no matter what stuff they go spurting around the fact remains they forgeted up and now they have to pay the fine for it. Getting others to post for them or bypassing IP bans quite simply ridicules the judgments of the community as a whole and the administrators.