I think everyone must find the most wanted song at least bareable, and I do think maybe 30-50 year old women might actually enjoy it. Although obviously it's terrible. The most unwanted song, surely everyone must find brilliant.
I don't think this is supposed to be scientific or anything - the guys who did it are (apparently) conceptual artists and the most unwanted is a really good representation of a deliberately bad song. Which makes it fantastic.
The thing is though, it's still got rhythm and it's very entertaining and it keeps you enthralled and gripped throughout. But deliberately unlistenable music, like grindcore or drone or dark ambient or whatever, Sunn o)) for example - I love that shit. Maybe 25 minutes of loud static would be more unwanted, but it wouldn't really be entertaining or good art or anything.