The most galling implicit premise of all is that every proposal for basic income I've ever seen accepts that BI isn't practically feasible with open borders, and therefore nothing changes at all for the class of people who work the longest hours in the worst conditions
(indeed their wage slavery becomes even more essential to ensuring future riders of the purple wage can still buy consumer goods)
An argument for implementing BI in the foreseeable future isn't really a "nobody should be forced to work" argument, as desirable as that might ultimately be. An argument for implementing BI in ones own developed country in the near term is a "nobody with the right passport should be forced to look for work" argument. I think social security - essentially insuring people from a risk of unemployment caused at least in part by policies enacted by an elected government - is a good idea, but I categorically don't agree that my fellow Brits should have an automatic right to receive more than the world average purchasing power adjusted income without even thinking about doing anything for it.
Your countrymen don't have to think about doing anything for it because their forebears and ancestors already thought about it, and already took the necessary steps so that later generations wouldn't have to.
They may have done it mainly for the benefit of their own heirs and successors, but now that it's done, it's done. All those improvements multiply, and Brits get more because it takes less individual effort to produce the same amount in the heavily-improved UK than in a country where improvements are more easily destroyed or converted. So anyone willing to obey British law, participate in the British economy (accept and spend pounds), respect British infrastructure, and assimilate into British culture should get more than the rest of the world, because those are the practices that allow Britain to be more productive than the world median.
A hedgerow along a country lane does not grow that way naturally. It takes an effort to force it. But once established, it just needs a regular trim and an occasional re-laying to keep the livestock out of the road. You just don't need to pull a new barbed wire fence in front of a blackthorn hedge, so why would anyone complain that no one is doing it?
The resources of the country are preferentially distributed to its own citizens because one country lacks the sovereign authority to force any other country to change its culture and institutions to be more productive. If those other countries wanted to be as prosperous as Britain, they could fork the British system, or selectively merge changes from it into their own repositories. See also: USA, Canada, Australia, New Zealand.
So those people aren't exactly thoughtlessly doing nothing. They are being British, as hard as they possibly can. And that allows the UK to have nice things like the NHS. In contrast, Americans, in being as American as possible, can only manage a hybrid public-private healthcare monstrosity that no one can examine too closely or for too long, because most of our psychiatric hospitals are cleverly disguised as prisons.
In light of that, there's really only one essential element that needs to go along with open borders. Assimilate the immigrants.
Arguing for suppressing the Western working classes on the basis that this will somehow help the working classes in the developing world doesn't make any sense. Labor is labor, around the world. You strengthen the working class in one place, and you've strengthened it everywhere. Pay a basic income in the West, and consumer spending can rise, aiding a rise in demand, leading to a tighter hiring market for developing-world employers who make the stuff, making labor actions for shorter hours and higher wages more successful.
Seriously, you consider me to be "arguing for suppressing the Western working classes" because I suggested that any right to earn more than the average global labour income even after cost-of-living adjustments probably ought to be incumbent upon them to actually doing some work? That's got to be the most intellectually dishonest characterisation of my arguments I've seen on HN.
Labour isn't labour when it's sitting with its feet up enjoying the privileges of accident of birth, and any benefits from their additional consumption that might trickle down to the developing world poor can easily be cancelled out if unconditional redistribution happens to have side effects on the Western economies in question. Not to mention the likelihood of barriers to entering Western countries getting a lot higher...
An argument for implementing BI in the foreseeable future isn't really a "nobody should be forced to work" argument, as desirable as that might ultimately be. An argument for implementing BI in ones own developed country in the near term is a "nobody with the right passport should be forced to look for work" argument. I think social security - essentially insuring people from a risk of unemployment caused at least in part by policies enacted by an elected government - is a good idea, but I categorically don't agree that my fellow Brits should have an automatic right to receive more than the world average purchasing power adjusted income without even thinking about doing anything for it.