Not running the trains should hurt the company's reputation though. But the problem is that due to decades of propaganda, the companies have successfully managed to convince the public that train unions go on strike for frivolous reasons, or even just to get some time off. At least that's the issue here in France.

Also idk about UK law but in France, the employees refusing to check tickets would be committing a crime, and we already have better laws regarding rights to strike than most of Europe...