Dakoom It would be something that will make a lot of people to use Flarum, just for that feature.
Franz quite a few security implications.
Convenience at the cost of security and stability is rarely a good thing
A webuser shouldn't be able to alter critical files (even though that happens a lot.. In any case, a new release can affect your install in unexpected ways. I recently had a core wordpress upgrade which went sour. Thanks to my manually run update (and noticing the issue immediately), I was able to revert an hour (rsnapshot) and fix the issue. Had it auto-updated at some point I might of noticed much later and lost days or weeks of changes (or everything - if the user doesn't back up).
I'm going to take this quote from another developer
As excited as we are about 17.3, upgrading blindly for the sake of running the latest version does not make much sense, especially if you’re already happy and everything is working perfectly.
