If people can afford to spend that sort of money then they must surely put some value on their investment, or do they expect the insurance company to cough up the total whack if things go wrong? If life was so crime free out there, then there would be no need for any of us to have insurance at all for anything. It is not just for floods, typhoons etc. I am delighted people have been lucky, I (so far at least) have also been lucky in my vans/motorhomes and cars from the blight of theft. My only bad experience in 35 years has been having the windows of my motorhome forced in a supermarket in France, fortunately only cash was taken. However, I still think taking as many precautions as I can is sensible. Having the van stolen is bad enough, but I think having it vandelised would be much worse because you couldn't get a new van and you would always know what had happened.
I don't have a drive to park anything on, so my choices in that direction are limited. Property values are also high here, a one bedroom tenement flat can set you back 150000 pounds while a house is 400k up to whatever you like. 2 bed penthouse apartments in the New Town are being advertised at starting at 500k, so somebody has the money. So I feel the majority of the Uk has similar problems regarding land availability. My storage facility is 10 miles away, but that's life especially when I leave the tools I need in the house.