Elon Musk didn't invent the idea of becoming multi-planetary, for safety purposes or otherwise. Sure he's advocated the idea, but I think it's a pretty natural thought to have when learning about dinosaur-killing meteors, the death of the Sun, etc. Lots of people have had the same idea for hundreds of years, some have fleshed it out more thoroughly with calculations, etc. It's perfectly possible to agree with those people without ever knowing about Elon Musk, much less "drinking his cool aid". Heck, it's possible to disagree with Musk/Bezos/etc. whilst being in favour of humans as a multi-planet species (e.g. disagreeing with reasoning, calculations, motivations, approaches, timelines, etc.).

PS: Elon didn't invent the idea of rogue AI either. Again, lots of people have considered this and calculated risks, etc. but his name keeps getting brought up as if nobody thought of this before. I've got nothing against Elon or his fans, but there seems to be an anti-Elon crowd who like to reframe in-depth discussions about some large, complex topic (space colonisation, AI, energy infrastructure, etc.) as if it's all about one guy, just so they can state their disagreement with that guy.