Re: Doesn't that mean the crap dish can't be replaced by new gear?
It has been admitted for a while regarding optical. That is why most UK optical astronomers are camping on La Palma, Rozhen and a few other sites elsewhere in Europe
La Palma is less to do with noise pollution and more to do with altitude. Ben Nevis stands 1344metres tall, Roque de los Muchachos Observatory on La Palma is ~2400m, so more than a kilometre higher.
This places it significantly above the weather giving you more observing nights per year than you could manage in rainy Blighty (i.e. much better ROI on your telescope costs, albeit with some increased costs for location), as well as being above the majority of atmospheric water vapour (again, see damp, humid, rainy Blighty) which causes distortion.
We have plenty of good, dark-sky locations in the UK. They're just regularly cloudy. This also affects certain radio observations where water-vapour attenuation is significant at lower altitudes, but by no means all observations. There are plenty of bits of spectrum which are entirely unaffected.