I've lived in Miami for 30 years and love the place. There are definitely things about it that take getting used to though, such as the large Latin and Island populations. And it's true enough that only certain parts of it are really attractive.
Also, it is a large metropolis, which isn't for everyone, but OTOH, it is hemmed in narrowly on both east and west by the Gulf Stream and the Everglades, so you can get out of town and into "the country" very quick.
Miami is almost tropical as well, which is unique in the continental US.
I guess it's what you're used to. I've visited a few times and it just didn't appeal (but then neither did Orlando). I lived in NYC for a couple of years way back when dinosaurs (like Nixon) ruled the earth and it was by far and away the worst place I ever lived. I didn't like anything about it from the self absorbed attitudes of New Yorkers to the constant smell of bus exhaust, burning garbage, and dog squeeze. Not to mention that you had to bribe everyone to do their job. The super would fix anything without a bribe, etc.