Speaking for myself, if I was allowed to edit on Wikipedia, I would promise to stay out of trouble, would avoid any controversial issues, and would edit on articles which I have expertise on and can improve. I admit that I made some newbie mistakes when I first started, I apologise, and I have now read the manual and understand how things work. Other people did do some things that upset my experience that they shouldn't have done, but I've already discussed all of that to death, and dealt with it as much as they can be, so that's all over and done with as far as I am concerned. And I am happy to go through having someone mentor me and with some restrictions. I get very upset about the poor quality of some of the articles which I have a great deal of knowledge of, and I feel like correcting them, to improve them, so that they are reflected more accurately for others to see, to use as a reference. I hate teaching schools and seeing kids get educated badly because they have used Wikipedia and get false or poor quality information.
But I am not prepared to give up on my principles, I will not ever accept that Wikipedia is perfect, nor will I ever suggest that Wikipedia is not a serious danger. I think that having inaccurate articles can change our version of truth, and that this is incredibly dangerous, and the most dangerous part of what Wikipedia is. I think that WP:OWN is a very important rule, and that we should be far more vigilant than we are with it. And I think that WP:NOR is regularly misused to suggest that someone that is biased yet has accurate important information has nothing to add. Of course I am biased about topics that I have a degree of expertise with. We all are. That doesn't make the information useless. It is much better to have biased yet accurate and informative information than to have unbiased yet inaccurate and useless dribble. And I would rather see people write about things which they have a degree of expertise in than to simply fiddle around with things that they don't really understand.
I don't know about other people who get banned, but I think that for most cases it is more of a case of a misunderstanding than anything else. Certainly any case that goes through the Arbitration Committee or has any level of discussion is one which can be reversed, provided that an agreement can be reached. Obviously serial spammers, hackers, and people who aim to destroy Wikipedia are beyond reform. But if it is debatable enough that it needed a discussion, then it is worthy of having an appeal.
And I don't think that a banned user should be required to apologise and admit fault in order to have the ban reversed. If you feel that what you did was the right thing, then why should you be forced to lie about that in order to return? We all have our beliefs, and keeping your integrity is important.