CX is great for my little jaunts around the city, exploring every little bit of wooded area/bridal path/footpath and linking it up with road/river bank/canal towpath.
I can't imagine taking my CX into the wilds of north yorkshire, an the brakes are not adequate for Hebden's technical descents (at least not for a man of my limited skill).
Everything has a place, I've been riding more road than MTB for a few years since I broke my thumb badly and couldn't grip mtb bars, but was ok on hoods/drops. I've now set my mtb up in a more XC approach, flat narrow bars, longer stem, narrow tyres and its great. I might even get bar ends!