Well, since it's late-night philosophy hour on HN...

"The whole denial of the possibility of empirical knowledge strand in modern philosophy has long rubbed me up the wrong way, but possibly only in a way that is clear to programmers."

I wouldn't personally go so far as to deny the possibility of empirical knowledge. But I would at least say that putting empiricism on a solid logical foundation is damned difficult, and maybe impossible.

"The denial usually derives from a distinction between the mind and the world outside it; things-in-themselves from the outside world can never be perceived by the mind, because all perceptions are mediated by sensory organs, they are all filtered one way or another."

Here you've hit a particular nail quite squarely on the head. In the English-speaking pragmatic tradition, there's been quite a lot of work devoted to getting away from that distinction and a few others. Mostly, these distinctions have been inherited all the way from Plato (with a few exceptions, like the analytic/synthetic divide that Quine so famously argued against), and the moment you accept them you also take on the nastiest briar patch in all of western philosophy.

So the modern (postmodern? Rorty had issues with that label) pragmatist simply says: you know what? If your theory of nuclear physics lets you build a working power plant, don't bother losing any sleep over whether it matches up with the way the world "really" is, because that's not a useful question to ask.

And there's quite a strong temptation to buy into that point of view. You don't have to muck around with the logical foundations of empiricism and all the clever traps Hume left behind him. You don't have to trudge through the metaphysics of propositions in the hopes of establishing truth as correspondence. And with far less work than you'd put in solving those sorts of tangles, you can even get a convenient system for judging competing theories and choosing between them. Curiously, it ends up looking a lot like Popper's attempt at a falsificationist basis for empiricism.

But it also comes under fire from practically all sides. The foundationalists don't like it, because it says everything they've been doing since Descartes was pointless. The relativists don't like it because it still perpetuates the notion that some theories are better than others. The metaphysicians don't like it because it (literally) throws them under the bus. And the average person probably doesn't care much for it because it doesn't match up with the "common-sense" view of the world most people adhere to in western societies, especially since most of what westerners consider "common sense" goes straight back into the tradition that starts with Plato.

Of course, there's nothing in this which says you can't still have a notion of "reality". It's just that asking whether something corresponds to "reality" doesn't seem so important anymore. Thinking of atoms as miniature solar systems, with the nucleus in the middle and the electrons grouped in orbits around it, almost certainly doesn't correspond to how they "really" work, for example. But thinking of atoms in that way does let you get a lot of useful chemistry done (it gets you the layout of the periodic table, and the reactive properties of the elements, and...). It won't help you build a nuclear reactor -- you need quantum mechanics for that -- but if you're not building a nuclear reactor, then why does it matter?