Just like Chinese Sky Lanterns which were also once acceptable, the time has come to ban disposable barbecues. They are a huge fire risk, burn the ground underneath them, are often left as litter & contain sharp pieces that can harm animals if trodden on. They are used in beauty spots, wildlife reserves, on beaches etc and just left smouldering. They make it far too easy for people to be irresponsible by putting them directly on the ground,  and then leaving them there afterwards. 

I live in the New Forest and we have had several fires locally in the last few days caused by disposable barbecues, including the huge fire in Wareham that took several days and 150 firefighters to put out. It’s been said it’ll take decades for the 200 football pitch sized area that has been destroyed to recover. 
I have nothing against barbecues, but the fire risk it too big, the environmental damage too great and the litter too plentiful & dangerous for these cheap, lightweight ones to be socially acceptable any longer.