I think it's pretty awful to compare the kind of explotation that goes on there with the UK or USA.
It's more reasonable to compare it to some other non-western countries, where you can have large gaps between the rich and poor and sometimes resort industries that cater to tourists, so you have rather poor people serving outsiders that come there for luxery. Or countries where people are politically opressed.
And there are lots of people who are somewhat, or even a lot, uncomfortable with those places as well. I know plenty of people who would never travel in China because they object to their politics. Or who do not do resorts in some places like Cuba because it feels exploitative.
But I would say that many people feel this much more strongly about Dubai. I think there are a few reasons. One is that the wealth extremes are just so very extreme, and the consumption so very conspicuous. I think the fact that the workers are imported in some ways feels much worse than employment in other countries of people who are on the lower end of the economic scale in some other places. It almost seems like a kind of trafficking whereas in places where the people employed at least actually live there, it seems part of a more natural economic order, and it seems to be done specifically so that those people have few rights.
I think there is an element where the ruling classes seem educated and urbane and the fact that some of their social practices seem very regressive seems even worse as a result. I think many people feel that those same ruling classes, while quite happy to take the money of westerners, actually would like to see them wiped off the face of the earth (maybe that is not accurate but I think people feel that.)
And finally, I think that luxery, air conditioning, and water, like that in a desert feels like a giant FU to the planet. "Sustainability" is really not on the table, no one can even begin to fool themselves.