Surely a factor. As is the deregulation.

I've been living in Germany for a very long time and the real decline started some ten years ago. At the beginning mostly because of poor maintenance. My first years with the DB 100 card (allowing to travel on all trains) were a pleasure then it deteriote to the point where you start yourself: where is this heading. As I said, the ban of SBB on German trains was a turning point for me.

But You're right about the networks being different (mostly because France suppressed many local lines in the last 20 years.