You don't understand the history of the two fanbases do you? When United started winning again in the 1990s, just as the premier league was formed and the sport became more globalised, City was in and out of the top league. As a method to cope with United's success and the world wide popularity we (and others, like Arsenal and Liverpool also got to a lesser degree) recieved as result of that success, City fans began to claim that they are the one true Manchester team. That most United fans, not just in the world, but in England, are not from Manchester but London or other places. Despite the fact that Old Trafford, even when we were relegated sold out consistently, and City failed to do that not just at the Etihad but at Maine Road too, didn't matter. So now that city has began to accrue a global fanbase, all of a sudden it's totally OK for city now. Ignoring the fact that they would always try and create this image that they were the real salt of the earth local team, when it wasn't the case, considering most of their fans are actually from Stockport and there has been studies to prove it.
Most United fans do not care if you support a club from a country you aren't from, loads of United fans on here, and Liverpool fans, are Irish for example. Always have been. All that matters is that it comes from a real place, not just chasing glory. Which is what your post seems to suggest to me. That kind of fan is not loyal, and as soon as city loses it's oil money or has a string of bad luck, most of you will jump to another club like PSG or Chelsea. I am assuming you are a genuine fan, but you don't seem bothered by that kind of false-loyalty.