Not just railway laws. Contract law has quite a lot to do with it too.That's a bit strong. It's not rubbish, it's just a particular point of view.
I was trying to look at it from a moral perspective, but I take your point about litigation. In that case, one could argue that the railway laws need to be changed to make them more equitable.
My argument (made without an awareness of the legal issues, I will admit) was: is it fair that standard class passengers have to stand when there are seats available in first class, just so the first class passengers don't have to share their space with standard class? I don't think so personally, but obviously opinions on this differ. Should the railway spend money, in rather short supply, refunding first class passengers if this happens? Perhaps, perhaps not. Should first class provision be reduced on busy services? I think so personally, but obviously opinions differ.
The level of provision (including zero) of First Class is a whole other debate.
Unacceptable and they wouldn't get away with it if l wanted a seat.Don't forget that a lot of people are too precious about having someone sat near them too and will occupy seats with bags etc. There's been instances of individuals having a bay of 4 to themselves and telling people to stay away.