You do need to know what you're doing, meet quality standards, and do things in a way that fits existing architecture (unless you have a really good reason to revamp something). It's not beginner-friendly for sure, but I can tell you the vast majority of non-upstreamed vendor code is not upstreamed because it's terrible (which is also bad for users: things like blatant security problems are much more common in forks than upstream).

If you can't be bothered to learn how to write linux kernel patches properly you shouldn't be making them at all, in a forked kernel or otherwise.