My range has quite a few separte ranges, and there are no restrictions on most of them.
I would NOT want to be shooting next to these 50's, but I don't see them very often. I think these guys with 50's come early in the morning or late PM so that they don't disturb others.
As long as the range has appropriate facility/berms to handle 50 BMG, and as long as the 50 owners don't disturb other (and they don't) they I think it's all good.
As for some ranges banning them just because they don't like the noise, blast, and "range" of the 50 BMG....I find that ridiculous. Perhaps it's an unfortuate repurcussion of some incosiderate 50 BMG owners, but to ban a caliber without any logical reason (like destroying berms and costing too much to repair, etc.), I find that to be a slippery slope. What's next then??