Most likely its just that the county officials there are willing to clear red-tape and expedite zoning/permitting/inspection for large corps looking to place high tech jobs there. Possibly negotiate property tax breaks too.
That would be my assumption as well: they're relatively similar in what they're looking for many of the same things: reasonable prices for land, water, electricity, etc., amenable local government, and reasonable housing + workforce. Intel's going to need more people but otherwise I wouldn't be at all surprised to learn that both lists of candidate locations ended up being very similar.
