When you want to put up a gigantic student housing complex to host 800 chinese university students for a great return on your investment but there's an abandoned Grade-I listed building on the site why would you bother going through all the council red tape and petty bureaucracy when you can just pay a 14 year old a few quid to set fire to it? If they get caught, they're 14 so it's a slap on the wrist. Now the remains of the building have to be torn down and you're free to build your chinese megablock.

This is how the world works I'm afraid.