Understandably, the hostile version ruffled a few feathers. I hope some of you enjoyed the post all the same. But let me now offer a friendlier presentation of the right-wing arguments for a UBI.
It must get awfully irritating to continually suffer Leftists accusing you of having an inadequate conception of justice. But I have good news for you! The predominant right-wing theories of justice are all far more substantial than Lefties typically realize. (Indeed, most right-wingers even sell themselves short here.) I bet you can't wait to see the Lefty's air of smug superiority falter upon hearing you explain how you too are committed to the institution of an unconditional basic income! The precise explanation will differ depending on the ideological basis for your commitment to capitalism, so I'll explore the alternatives in turn.
Let's begin with the deontologists. A very common right-wing thesis is that individuals can only be morally bound by negative duties, or duties of non-interference. If you affirm the fundamental importance of negative liberty in such a way, then liberals get all huffy and attack you for having an impoverished conception of freedom, or they dismiss your system of rights as an "empty formality" that's insufficient to protect the vital interests of persons.
Next time a liberal tries to paint you as this straw monster, feel free to throw back at them my post on significant negative duties. It shows how a fundamental commitment to non-interference can have very substantial consequences indeed. Libertarians who take liberty as their fundamental value have the theoretical resources to rival any leftist's concern for the poor. This might stem from their recognition that enforcement of property rights -- though a vital precondition for a flourishing society -- entails a socially-imposed unfreedom for the poor. They will thus want to do what they can to alleviate this imposition; and the freedom granted by the UBI would be a great way to achieve this.
Propertarians (libertarians who take self-ownership as their fundamental value) might be skeptical of the above reasoning. But other arguments remain open to them. For instance, they can appeal to the principle that demands of morality must be reasonable demands. Since it would not be reasonable to ask a starving man - who has exhausted all other means to meeting his basic needs - to sit back and die rather than appropriating surplus goods from a rich man's holdings, it cannot be the case that the starving man has such a duty. So the rich man cannot have any absolute right to his property that would entail such a duty.
Now, we want to institute a defensible system of property rights. But the only way we can achieve this is if we take pre-emptive measures to ensure that the kind of "unreasonable" situation described above will be avoided. So even though you wouldn't countenance the incoherent notion of a positive moral right to welfare, you have sufficient grounds - based entirely on legitimate libertarian reasoning and negative rights - to institute a positive legal right to welfare. Paradoxical though it may sound, you should institute the UBI to protect your property rights. With it, your post-tax holdings will be rightly inviolable. Without it, there is no such guarantee.
Around this point, the squawking Lefty might return to his straw monster: "I thought you propertarians all held that taxation is theft, effectively indistinguishable from enslavement and forced labour!" Just laugh patiently, and remind him that it's only theft to take another's rightful possessions, and that you're addressing the prior question of how much of our holdings we have by right.
A crucial Right-Wing principle here is the Lockean Proviso, which entails that property owners owe compensation to the propertyless who are deprived access to material resources that would otherwise be available to them. You still insist that individuals own their labour, of course. But their resulting property is not solely composed of labour; it also involves material components. And your appropriation of those natural resources harmfully interferes with others, as explained above, and thus violates their negative rights. So the right-wing principle of rectification for past injustices straightforwardly entails the duty to recompense others. Again, the most reliable way to effect this rectification would be through the institution of a UBI. (Just imagine how the Lefty's eyes will pop when you explain this to him!)
So that's the deontologists sorted. Let's now turn to the utilitarians. I must admit, I like you guys better. In fact, I am one myself. We have some empirical disagreements, of course, which is why I'm slightly further left than you. But we share the fundamental commitment to not letting ideological fetishes get in the way of good policy that will improve lives. Now, there are a host of reasons to think that a moderate UBI could improve most people's lives -- I review some of them here.
What I want to do now is address the committed free-market ideologue, who insists that a perfectly free market is the best possible system. Let me begin by noting that to some extent I share your respect for markets (though I can't rival your enthusiastic optimism), and wish more leftists did too. However, I think the UBI is a crucial complement and precondition for a well-functioning market, for reasons explained in the linked post.
But even if you don't buy that, and continue to hold that a pure free market is ideal, still you should support the UBI as a step in the right direction. It is obviously a huge improvement on standard welfare schemes, with their perverse incentives and subsequent "poverty trap" -- problems of which right-wingers are all very aware (though leftists too rarely listen). Further, as explained in my post 'Basic Income for the Economy's Sake', the UBI would offer workers sufficient protection that minimum wage laws and other pernicious labour regulations could be completely done away with. Even if not ideal, it would at least bring us much closer to your ideal of the free market. Surely the combination of market + UBI is much preferable to the tangled mass of regulations and state-subsidized benefits that currently beset our economic system.
So join such right-wing luminaries as Milton Friedman, Charles Murray, and the philosophers at Right Reason, and support the UBI. (You may prefer to call it a "negative income tax", but so long as it does the same thing, I'm not worried about the name.) Brush off the straw, spread these arguments, and prove to liberals that they don't have a monopoly on justice. The depth of your own theories commits you to no less.