It does seem to be a UK thing. When abroad everyone seems to leave all their stuffs on their bikes when they go for a wander round the sights. In the Uk I've had saddles nicked, even a cheap plastic one while in Sainsbury's for 10 minutes, tyres slashed, and even a frame bent.
I stayed in Switzerland on what was basically a council estate (Switzerland is ridiculously expensive) with drunken chavs wandering through all night. The host told me not to bring the bike inside (which I ignored once he'd left) and pointed at a bike parking area with one of those curly wheel bender stand things. There were a number of mid-priced bikes in it with cheap locks through the quick-release front wheel. They were all still there in the morning.
On another occasion I stayed in Greece. The hotel owner said "Just leave it there, against the wall, it will still be there tomorrow". I am 100% sure that was true, nothing else was locked up and was all untouched the next day, though I insisted he open the garage for me.