Why do UK talk shows never have musically diverse guests?

Just seen that Metallica are doing a four night residency on Jimmy Kimmel in America, one of the most popular late night talk shows in the USA. And they're far from the only rock or metal band who has appeared on Jimmy Kimmel. Likewise the other popular shows, like Colbert and Fallon, would also have a lot of diverse musical guest stars. Then look at Jonathan Ross, Graham Norton, even the One Show...it's a revolving door of Britschool pop stars at best, and 80s-90s comeback stars at worst. This isn't a "metal is better than everything else post", it's just a matter of variety and diversity. We've lots of amazing UK based rock acts here as well, and I've never seen a single one of them appear on any of our mainstream talk shows. I know Graham Norton openly hates rock music (as he tells us every Eurovision) but what about the rest? Why is this the case?