There is inequality everywhere, all over the world. 'Slaves' who work in Dubai for a few years go home and build a house and are set up for life.
Seriously? You cannot be that blinked. Some people land on their feet and wages promised to them and can save up. I'd argue you're looking at 10 years at least for most low paid workers to save up enough for a house though (and 10 years is not 'a few'). Maybe less with no recruiters to pay back home and limited other financial obligations but that's still several years of hard work, living many to a room, working outside in 40-50 degrees in the summer and getting to see your famik once two years.
If people sign up for that, with full knowledge and the money is worth it for them then fine.
However, a lot dont get what they sign up for, don't get paid, live in horrific conditions and have their passports held. There's also a horrific attitude to low paid workers, they're just considered lesser than others.
There are fantastic things about Dubai and the UAE (I live here) but you need to stop kidding yourself that all those guys in overalls are blissfully happy knowing two years graft and they can go home and build a house.