It is colonialism turned inward. Every spiv and his dildo wants a paddock with a coterie of cheap skivvies to press the shirts and mop the shower rooms. We've been fed the dream of colonial mastery for so long it became an unbearable yearning.
Seems everyone and their monkey-heart wants to be a colonial steward, living in ivory towers with a major population of cheap helots to carry them in sedan chairs, affording the kind of patronizing they feel to be their long-awaited due; the servants gleefully shaking the cocktails, with the dreaming of becoming Trimalchio's themselves one day, with their own court of au pairs, jesters and naked man-friday's.
Everyone wants the ostentatious dream, not merely nasty aristos and their foreign oligarch apes. Those leftists with relatively superior educations ('uni' - says it all - university-lite) and private property welcome immigration for these reasons+, hoping that masses of man-mulch beneath their sandals will raise them up in sheer material status (due to filling the rents on the bottom rungs)* -for they are, after all, soulless self-proclaimed materialists- They can be that ex-pat everyone knows, 'living abroad' somewhere like Malaysia, or Thailand, with an army of de-personalised gurning eunuchs at the beckon, being paid pitta-bread money.
This is the real purpose of the pro-immigration brigade: the supreme late-decadence of "It felt special on holiday, I want it here full time, so please bring in banana boats of hapless human-tools and make them fight for crumbs of employment with dwindling wages at our feet". Meanwhile governments shall slowly phase out the euro-dole because of the inevitable, interminable grande recession (helped by fresh millions or of humans haplessly draining the circus)#.
So we're taking third-world snapshots and saying "Yes, cheap lackeys here too please !" - 'A service economy'.
Just like the aspiration to free ourselves of the working burden of making our own things was only made possible by sneakily setting up a much larger network of liberal-economic sweatshops all over the far east, Saharan Africa, Turkey and the middle east, so now everyone wants not only to free themselves of all meniality, but to acquire a kind of Edwardian Aristo status we see in the endless (utterly relentless) Jane Austen and Downtown esque productions, albeit on micro, ex-pat scale.
Because
these lordlings are shorn of all true noblity, since they feel sick and
loathing looking in the mirror at their lonely visages without the definition cast by the shadow of helotry.
+The Oligarchs are against immigration because they can afford staff; the typical London fat middle class will be for it for humanitarian reasons, but really because they'd like to have a choice of exponentially cheaper builder lackeys and doorknob polishers.
* but what if those on the middle rungs bail out of this grisly game of musical chairs ?
#The Huns welcome 'economic migrants' because they sorely need raw labour to continue their industrial building machine that makes them "Supermasters of Europa" while having a declining birth rate as their native sons aspire to something more (read: finance sector) than the basement factory floor of Vorsprung durch Technik, for being the weathiest nation in Europe, they don't wish to raise themselves up anymore as reprobates of the war with the guilt-driven slave work-ethic.