Yes I was aware of France's abusively high track fees.
I'm just noting a societal phenomenon that IMO affects France in particular, as it happens. Many of the same people who complain about night trains being axed do not in fact take night trains themselves. Aspirational night-train passengers, you could call them. They themselves take cheap flights, which are objectively easier, more comfortable and (uh) cheaper.
French night trains, which I have taken a number of times, are not very full and not very good. I know things are better in central Europe. Personally, I'm convinced they will never be the answer to planes. If they were, China would be investing in them and not in high-speed rail. The market for night trains will never be more than a romantic footnote and I wish we would not be so distracted by them.