I agree in principle, OP, but I don't know how you'd 'police' it in practice.
But I have no patience or sympathy with people who take the piss with the NHS. If there were some way that selfish, stupid people who waste time and resources could be made to take the consequences, I'd be all for that. Yes, I really would, before anyone says 'But what if they NEED to be seen first?'
There is so much structurally wrong with the NHS, there's no easy fix for all its problems, but allowing people to muck about and waste everyone's time is crazy when resources are limited.
(One eg - and not quite the same thing as you're on about...
On an exceedingly hot day 2 years ago (40 degrees - warnings not to travel unless absolutely necessary) we had an appointment at hosp to get my husband's biopsy results. We got bottles of water, wet towels etc for the car and set off, labouring up the hill from the car park in the heat. Got there 20 mins early but were told we couldn't be seen because the previous appointment people were late...and they ended up being an hour late. Why couldn't the consultant have seen us first (appointment only 10 mins)? No explanation given.
Oh, and when we finally got in, he said 'Oh, I'm so sorry - you've had a wasted journey - the results haven't come in yet!'. Why, on that day of all days, couldn't someone have contacted us to save us that nightmare journey and 1.5 hours wait? Aaaarrrghhh. It's not rocket science.
Although I have no complaints about clinical things, I nearly always experience admin issues like this one with the NHS.)