They aren't unwanted in their home countries. Chips on shoulders, hair-trigger outrage and shouting at any perceived slight or insult, hating anyone outside of their own immediate families or tribes--that is just part of Arab culture (I won't bother with the perverted parts here) and how almost all of them are.
I thought the deal was that Assad was trying to persuade them to leave by various means, and that the Western leaders view them as an ISIL recruiting pool (which might explain why Assad wants them gone).
They are probably the people who want to overthrow Assad. But that doesn’t make them good, and it certainly isn’t preventing them from acting like rude spoiled princelings who treat the rest of the world like the hired help.