Yeah, I decided not to boil in one too, although I've every intention to continue using a boiler for many years so a stainless one is still a good investment for me.
The American forums have historically been a bit more gas-oriented, and also stainless (amongst other stuff) is cheaper over there too, so they probably have a bit less temptation than we do. I'd be pretty happy to stretch one of the blue barrels as far as HLT temperatures myself, keeping kids/pets away and all that, and even happier with a thick-ish polypropylene one, as pp is far less affected by boiling type temperatures than HDPE is (copperkettle do some 60L pp euro bins that they say are suitable for boilers).
But theres no doubt metal is safer - especially if (as many people do) you remove the boil-dry/over-heat protection from the elements you put in it.
Cheers
Kev