I read these threads which seem to pop up regularly, with incredulity. I have been fortunate enough to have been to many of the places listed, some of them multiples of times and I have yet to find a place I found overrated.
Some I liked more than others for sure, but I have always been happy to see and experience other places.
I do lots of research before travel and never go to resorts and I choose places because I have an interest in something there.
I adore Dublin, and have no idea why it attracts as much hate as it does on here. In fact I am heading there this weekend to meet friends and I am really looking forward to it. I go between 4 & 6 times a year, sometimes for work, sometimes pleasure, often a combination. I went to university there many years ago and still love it.
Ditto with Paris - I absolutely adore it and always have the best time there, so much culture - art, literature, architecture, etc. I could easily live there.
I visit Italy annually for work and cannot understand anyone hating Rome / Florence / Venice etc. They feed my soul when I visit. Again I could easily live there.
There are places I have zero interest in visiting - Dubai, any of the Disney's, huge AI resorts, waterparks, theme parks etc so I'd say it's actually a difference of expectation of what makes a good holiday that causes people to be disappointed in some places?
London is fine, but it's not better than New York or Paris or Sydney or Hong Kong or Bangkok in my opinion, they're just different places with different things to offer.