Why would they buy then? By adding the ability to make your own track, is about the same idea as giving Demo drivers more cars. THATS WHY THEY DID IT! They were smart to not let us design our own tracks. Just like the other cars and tracks, THIS does give us the motivation to but a newer license.
I disagree with your comment, simple as that. I'm not trying to be rude or selfish, just trying to prove a point from a business stand point.
I'm for allowing all content in demo, but only replay from S1/2 users without any driving allowed.
For BL3, allowing demo users to drive on a few pre-defined AutoX style layouts (including those used in training) would be fine. Otherwise the car park is a boring place.