I've always been a user of the Debian and Arch worlds. The RHEL/Fedora/etc world has been this "other" part of Linux that I frankly haven't touched much, and haven't yet found a reason to.
One thing I'm not totally clear on is what specifically Red Hat offers that people pay for, i.e. what are the details of the "+ stability + patches" of what GP mentioned. Are there paid applications as well? Is paid support a large part of the business model? And so on and so on. I'm still just a little mystified by the RHEL business model, and every time I hear someone talk about it, it's literally vague one-word answers such as "stability," "patches," "support," "enterprise stuff," etc. Even the RHEL FAQ offers essentially just that.
I'm still not quite informed enough to be able to confidently lean one way or the other, but I have to say that I can't shake the feeling that RHEL's business model ultimately relies on exploiting their customers' desire to change their systems as little as possible, even if it means the customers eschew more modern systems that make obsolete the need for the kind of products and services RHEL provides. Or to put it another way, RHEL enables their customers to live with "the devil they know," and not adopt more modern best practices. Which isn't necessarily a bad thing, I get it, but also if that is indeed the case, it seems like a rickety foundation upon the already rickety foundation of trying to sell open source software that easily be unseated by, say, the nix model of doing things.
I don't know, I could be dead wrong, but starting from what I've seen most other tech companies do and mixing it with a dash of "the idea of paying for Linux seems insane to me"...in lieu of better information, I can't dismiss the above out of hand.