I think it's a bit of a stretch to say this is a Irish bashing thread. That's chip on shoulder territory. (Well definitely is chip of shoulder, with overtly defensive comments involving the word English or England.)
People don't like it to visit- so what? I can understand why someone might like it.
There are more interesting and beautiful cities - get over it!! Dublin is still worth the visit for many. Lots of people love it. If you stick to the city centre for a few days it's hardly crazy to imagine how it get a bit tedious and the expense annoying.
I've been to cities I've not particularly love, and wouldn't suggest it to anyone. Other people seem to love them.
Glasgow, been mentioned on this thread, nothing interested me when I had free time there and was more than happy to return to Dublin.
Belfast, once I'd gone to the titanic and a tour I was done. Had some nice food there, but nothing to make me thrilled enough to go back.
Your experiences shape how you feel about a place. I hated Amsterdam - endlessly harassed by men as a lone female. Anne Frank's house, Van Gough museum all amazing to visit but being groped and followed around really took any goodness from.
Brussels = dull as dish water. Possibly duller. Might even actively tell people not to go there if someone started a thread asking about it.
Cork has been mentioned a few times. Cork city held nothing for me. Everything I ate was poor quality. Utterly different to the rest of Cork; loved west cork wouldn't bother my barny going back to Cork city though - probably tell anyone who asked not to bother with it.