I never thought about reboots as fan fiction, but in a sense that’s exactly what they are: sanctioned and well funded, but fan fiction nonetheless. I think the rash of poorly made reboots is a direct result to fan fiction not being very good. Fan fiction is usually poor because those writing it are not very skilled writers. When it comes to films like Star Trek Beyond the writers should be among the best. They’re being paid enough for Christ’s sake. That doesn’t mean they’re infallible. Their problem is likely due to being too close to the material.
Star Trek TOS had it’s day. The reboot has had three films to get its shit together. Enough already. Let it go.