Perhaps I did not think it out too thoroughly, I composed it after I woke up too soon, but I do think that some players have helped with GMRPs, perhaps only with one-shot characters. I could be wrong.
As far as I know I have ended up on only one ignore list and am uncertain if I am still there. I do believe that some people are too quick to ignore as it is very easy. What Nikodemus was saying makes sense to me that annoying players ought to be tolerated as much as possible rather than just written off. People definitely have different moods and role players tend to have an artistic bent, i.e. be variable and more unpredictable than others. Too much seriousness can often be followed by madcap Keystone Kop behaviour.
It seems to me that if you are someone with a long permanent ignore list my suggestion would not bother you much because you wouldn't be removing players from it in the first place. However since the list is actually locally kept and not on the server it would likely be too much trouble to change to support my addition to your idea.