There was something similar a while back, while there are few places I will say I will never go to, there are quite a few that I will never go back to.
No interest in visiting Mexico and I've never had much of a desire to go to South America.
Always said I wouldn't go back to Indonesia, I haven't been to Bali, but some of those resorts look good!
Things change, a lot of places I've been to, I wouldn't/couldn't go to now. The opposite is true as well, a lot of places I couldn't go to when I was young and traveling a lot, you can now, Vietnam, Laos, Cambodia for example.
So my duck-it list includes places I don't want to go to nor to go back to, Israel, Mexico, a lot of South America, Zimbabwe, Belarus, Turkey, current war zones , Morocco, Tunisia, Libya, a lot of the PRC and some of India and others. Also a lot of the USA, I felt more unsafe in some parts there than I did in Lagos or Nairobi.
Always wanted to go to Bhutan, but after what drron wrote a while ago I'll have to give it more thought. Myanmar was high on my list to visit, but now I'm not so sure.