I suspect this is in refernce to Banks's stated purpose for writing the Culture series.
>He first conceived the Culture in the late 60s, and has developed it ever since. “It’s basically a lot of wish fulfilment, I write about all the things I would like to have,” he says. “I’d had enough of the right-wing US science fiction, so I decided to take it to the left. It’s based around my belief that we can live in a better way, that we have to. So I created my own leftist/liberal world.”
[1] https://spikemagazine.com/iain-banks-interview/
Given Musk's red-pilled foray into right-wing culture war discourse, it is indeed ironic that he would revere these books.