> the fact that protectionism is bad in the long term
It all depends, some industries are just not working privately, the privatization of electricity in France was also a failure for example. The privatization of the post system was also a failure but it matters less since the postal system is less important nowadays.
For the trains, the core issue here is that the network has a value has a whole, if you start to remove the unprofitable parts, it reduces the value of it as a whole. It would be like having only highways, it would not be useful even if it's where you have the most traffic.
> and illegal in the EU.
Well, then you understand why some people become anti-EU when their public service fails and politicians tell them it's perfectly normal and because of some EU policy.