Why does the BBC have to have balance at all costs?

Because it's publicly funded so it has to be seen not to favour anyone. Unfortunately it bends over so far backwards to be seen to show all points of view that this includes giving airtime to nutcases. Oh well, I suppose it gives us the chance to work out for ourselves that they are nutcases. Call me old-fashioned but I'd rather have that than deliberately biased reporting.

As long as it still has people from both the left and right wings complaining about it, it must be doing something right.

Still better than the US approach