IMHO it is usefull to check if a new version of CMSimple is available and offer an automatic upgrade.
This is important for noobs and for webmasters too who has changed by example the lang files. So this new function has to upgrade not only the core files (and the plugins contained in the standard download package) but has to check for changes/additions in the config, css and langfiles too. This seems to me the harder part, but I may wrong.
FWIW: as of CMSimple_XH 1.6 the plugin UpdateCheck is bundled, which checks for available updates. Automatic updating is not yet available, though.
Closing, as feature request should be filed as issues on our Github page now.