What's with the British... taps

OK, this is a consistent, albeit minor annoyance I've noticed since moving here. For some unfathomable reason, the British seem to insist on having separate hot and cold taps, rather than a single, adjustable one. Now, on the face of this, who cares? They're taps, it's not the end of the world. While this is true, it leads to the totally flummoxing situation where I have two choices when washing my hands; nearly-glacial cold water, or water so hot I cannot hold my hands under it (seriously, without hyperbole, the taps in the men's room in my office building dispense water so hot it steams). How is this useful? Who uses the hot one and where did they get the sub-dermal asbestos? But more importantly, is it really that tricky to get a tap which has an adjustable temperature?

See the rest of my "What's with the British..." series.