There's no lack of "allowing" compatibility. The headsets function very differently, meaning the developers need to put significant work into adapting old titles for PSVR2. They are all free to do that, and some are. (As the owner of many PSVR games, I hope a lot more titles are ported than have been announced.)

Your expectations for VR seem a bit unreasonable IMO. It sounds like you want VR to fill all your gaming needs, with underpriced hardware sold at a loss and a steady stream of new AAA titles to play.

Maybe I just don't game enough but I was very satisfied with the offerings on PSVR, and I would bet money that PSVR2 outsells that headset and ends up with a far, far, FAR superior library, even if much of it is ports that are now graphically feasible thanks to foveated rendering.