I think you're confusing two issues, that of whether the class is fun and what the OP actually asked.
We often see this kind of defensiveness about Monks. It's like "HOW DARE PEOPLE DISCUSS MONKS CRITICALLY! I ENJOYED PLAYING ONE!!!", which like, I can understand, I've seen similar threads re: Bards and I like playing those, but it's fundamentally missing the point to come in and say "Well they play okay in 5E!" (which is true) when the thread clearly outlines the two issues it wants to discuss:
the class that has never really be done well.
the class that has never felt properly integrated.
You can have a class which is fun to play but hasn't been done well - i.e. it could be overpowered, it could be underpowered but fun, or it could simply, as in the case of Monk, be an overspecialized concept which is standing in for a much broader concept. And it's hard to deny the integration issue, which again stems from the issue that Monks are, conceptually, very specialized, and whilst 5E has tried to branch that out.
To be fair to you, you're not being quite that defensive (though "have you played a monk??!?!" doesn't come across as a very honest question), but I think it's pretty tiring to have the same "WELL I HAD FUN!" interjection over and over and over in literally any discussion of Monks. It's not like I go into every discussion of Bards and do that. If I do discuss them, I actually engage with the thread topic, rather than just saying "I ENJOY BARDS!!" (which I do).
Frankly if "fun" alone is a defense against all critical discussion and a reason to include a class, then it's a crime we don't have 2E Psionicists in 5E, or 4E Invokers or Warlords or Wardens (or indeed quite a few other classes in 4E, including a proper version of the Avenger).