American Jews are by and large spoilt, obnoxious, demanding and LOUD eg Alan Dershowitz & Dov Hikind!
If they ever have to flee to Israel WITHOUT their money, the Israeli Immigration Authority will slap on such a tight quota that it will make the 150/month Falash Mura quota look generous!
Worst of all would be the 1 million US black-garbed Haredim coming on Aliya without their gelt: all of Boro Pk, Williamsburg, Crown Heights, Monsey. Flatbush, New Sq, Lakewood etc etc would spell the end of the Medina: "The Moshiach will come from the USA!" (Malbim 1870)
Any truly mass US/UK/Australian/S.African/S.American Aliya would involve the Netanya Beach ma'abarot tent camps of the 1950s being reinstitutionalised!
And of all those worthy of coming on Aliya, the ONE GUY they davka WON'T allow in is Chaim ben Pesach!