Why are electric showers so old-fashioned looking?

I'm just letting off steam because I can't find what I want!!!

We wish to replace our electric shower with something more modern, but despair of finding anything.  We have 'state of the art' new taps, and yet the only electric showers available are just a redesign of the plastic box my mum had fitted back in the 1970's!  This seems to be the only real offer:

Why can't electric shower manufacturers fit their electric bits and pieces into something more like this, which is much more the sort of thing we're looking for!