UNIX for Advanced & Expert Users

As much as I love unix, in particular it's derivatives linux and mac, I must say it's a b*** to code software for. I used to maintain a PHP project back in the early 2000s, which I won't link to as I no longer maintain it, and anyway, basically it was a PHP based personal organiser. It worked and still works like a dream but I used to get complains from downloaders with hosts with safemode enabled that they had to go through the process (if they didn't know PHP) of chmoding the config file, installing and then chmoding it back because their unix system doesn't let PHP open and save to it otherwise. I know this is the same for almost all PHP software that people have to chmod config files, but I ask, why?

Why can't unix just let PHP files in a user account when run by someone visiting or the owner in their web browser as belonging to that user? Rather than belonging to that web server's user or to that php installation's user or whatever the reason is?

It's a pain in the ass because unless we tell users to leave their config file chmoded to world writeable, there is no way that the users can update the file each time they move hosts or servers via PHP softwares' control panels.

Any plans to change this?

Change what exactly? If a default installation of PHP does not work how you expect, you want UNIX to change?

Actually most versions of UNIX and derived OSes can do this with acls.