Because Mint is popular among the crowd, and such challenges are also driven by the crowd. Better to see it as some social or meme dynamics, than to explain it with logical reasons. I also see more new users who use arch, because of the “I use arch BTW” meme.
As a Fedora Silverblue user I find it hard to recommend it to new users. It’s not an issue with Fedora, but with the state of Linux desktop in general. At least with Mint/Ubuntu people can rely on social media and the community if they have problems. And Fedora is a more niche thing, and doesn’t have a big crowd.
Moreover, I chose Fedora because of my experience, which allows me to have opinion what is better. But I don’t think it’s a good idea to explain the years of the Linux desktop drama to new users, when they are just doing the first steps or trying to feed their curiosity.