Well .. since the last blast in Ramadi .. we have basically LEFT Saudi soil. There is nothing but a skeleton crew there anymore.
Yes, they are considered an ally, however, so is Russia - but that doesn't mean we are going to sit still and allow either of them to jeopardize our security.
As far as "having to be careful about ... and changing the home of Mecca and Medina" - who said we were even going to try to do that ..?? I don't see any relation to our security and location of Mecca and Medina.
The "sad truth" is I don't think you know what you're talking about.
Get yourself aquainted with the region and its issues, then comment.