The tap issue

OK, we are in Britain, have I mentioned this? Diferent country, different culture, different habits. At least the language is understandable. Sometimes.
But those faucets, man, those faucets! I just can't get it! And so can't the Brits themselves, it seems.
I have already tapped into this subject before (no pun intended), but I'll elaborate: it is common in the U.K. to have two taps on a sink, in the bathroom or in the kitchen. One for hot water. One for cold water. Steaming hot. Ice cold. On. Off. No in-betweens. The digital water system! Arrrgh!
"There must be a logical reason for that. Or at least a historical one." I thought. And I guess that I am right about the historical one, although nobody was able to confirm it to me.
It is quite clear that you are expected to block the drain hole, pour some hot and cold water into the sink into the temperature mix you want and use the pooled water for whatever use you have.
Yeah, right. That must have made sense 70 years ago when a mixing faucet was really expensive, but nowadays? Doesn't convince me, as I see this arrangement in places where the investment in mixing systems would have been definitely covered by the construction budget.

But it is also frustrating when they try to solve this problem by actually installing a water mixer. Like in the kitchens of Lakeside 4. I was delighted to see a mixing water tap in kitchens there. "How lucky they are" I thought. Well, not that lucky. If you take a closer luck at the photo below, you'll see why.
Note that there are two streams coming out of the tap. And yes, you guessed it, one stream is hot, the other cold. In theory, they should mix in the air, and all would be fine. In practice, it doesn't work that well. So, even if they try to solve the problem, it doesn't really work!

So one has to take the matter in his own hands, and be inventive. And really, it is not difficult. All it takes is a PET bottle, a Swiss army knife and 3 minutes, and the problem is solved a bit more satisfactory. No, it doesn't look great and yes, it is a bit fiddly to work with, but, so far, no one has burnt their hands under the hot water any more.