York probably would make more sense than Leeds given that it's already got a Dungeons there.It doesn't really surprise me, i think it actually makes pretty good business sense as I can't imagine many of them make much of a profit, and really once you've been to one you have been to all of them. Add to that there are sea life attractions at Alton Towers and Chessington and you further reduce your potential visitors who may have been to one when visiting a theme park.
I hope merlin use the sale of these attractions to open some more unique attractions in the UK. The mini clusters work well with visitors combining attractions to make a visit worthwhile.
I do wonder if merlin would consider looking at any other major cities for clusters. Bristol, Leeds and Edinburgh spring to mind as potential locations. I imagine living near a cluster means your more likely to buy a merlin pass so this could make business sense as merlin will be aware of geographical gaps where the passes don't sell and where they do.
Surprised they have never tried to buy Jorvik in all honesty.