For what it's worth, I was deadheading SAT-CUN the other day and sat next to a USAA mid-level manager. We were talking, she asked if I was a member and I said "yes". She asked if I had any feedback, so I told her I have always been satisfied but I mentioned this thread and some of the points made, primarily the one about the expanded member pool.
She listened and then explained (I'm sure I didn't fully grasp it all) that the member pool is not one amorphous group. "Risk pools" are established based upon status (I'll leave it at that). Not everyone who is a member will be quoted the same rate. Also, they are pulling out of some areas, basically continuing to cover existing members but not offering coverage for new members in some geographical areas where they cannot keep premiums at a reasonable level.
It was the first time I've ever talked to an insurance person where I didn't feel my eyes glazing over after about 2 minutes, which was nice. :-)