I am sure that any rules would be set reasonably sensible after taking all factors into account. But in any case, your argument is a very weak argument, as you could potentially use it to get rid of any regulation or limitation.
"Requiring people to have a blue badge to use a disabled parking space is unfair. After all, disability is so subjective and can be hard to measure, and there is the risk that a few people in marginal situations might feel hard-done-by. Let's remove the requirement and let people decide if they think they are entitled to a space or not."
Concern about a few difficult "edge cases" grumping that they feel they are just on the wrong side of a rule, has to be weighed against the overwhelming harm caused by the fact that tons of not-remotely-eligible people are going to be parking out all the disabled parking spaces, meaning people who really need them won't be able to use them.
The growth of woodburners in urban areas has caused the toxic air pollution they create to double in a decade. We need to do something about this. It is shortening lives, triggering heart attacks and strokes, increasing the risk of things like Alzheimers and Parkinsons, not to mention the stink. Can we all please have a bit more worry and concern for those who are developing preventable diseases as a result of this stuff?
If you don't like the idea of any restrictions, period, just because you don't like the idea of having rules about this kind of thing, then I suggest you direct your anger at those who have made the coming crackdowns necessary by "taking the piss." If woodburning had remained a niche rural thing that you get in farmhouses and low-density villages, causing few issues and being done for understandable reasons, then nobody would have seen the need for any particular rules. The trouble is that very large numbers of people in suburbs and urban areas have taken these things up and started using them in the past 20 years, causing health and pollution problems that are increasingly hard to ignore, and prompting the calls for a crackdown. Be mad at those people, not the people who want there to be some rules because they are worried about their families' health.
Wood burning air pollution in UK has doubled in a decade | Air pollution | The Guardian