There will, and I've seen one case on the news where I have tremendous sympathy for the person involved given her specific circumstances. In general, though, my sympathy is scant; anyone travelling at the moment will have done so in full awareness that border requirements can change drastically, expensively, and at minimal notice, and have had far more forewarning of this change than of some of the other quarantine requirement changes.
As for judicial review, the power of a resolution by the Council of Europe or WHO is of minimal legal effect and, given the failure rate of judicial review attempts to date, I see little likelihood of the hotel quarantine requirements making a material difference to the odds of success of any further attempt at judicial review.
I would also suggest that the comparison with imprisonment is mistaken. There is no suggestion that any such traveller has committed a crime, just that their travel represents sufficient public health risk that it is deemed necessary that they go into a specific form of quarantine for long enough that it is possible to be certain that they are not ill.