answer seems to be "it depends" on the airport and also, yes, on the individual checking.

Remember that the check at security is just to comply with the "only ticketed passengers in the secure area" rule. So it really only pertains to your ground access...you have to produce that ID to get on the plane. And the "only ticketed passengers" rule was primarily implemented to reduce the volume of people passing through security.

The first time I went thru security without ID being checked (at MSP in October) it kind of bothered me, but since then I haven't really noticed.

Personally I'd like to find a way to change or amend the current situation as I often would like to be able to meet colleagues who connect at ORD for a quick chat.