[fragsworth]

Clean URLs aren't really necessary and can be difficult with some frameworks.

Automated backups also aren't necessary for all sites, particularly if the entire site is in a source repository somewhere and doesn't have users.

[r0s]

Clean URLs are just as useful and visible as the favicon, or custom error pages, or many other "unnecessary" features.

You need to backup production sites. A repo could do that, but it's just another backup system that needs to be implemented and verified.