I guess it's nice for non-technical people who don't know how to use `about:config` but beyond that I don't really see the need. Hopefully adding that extra layer of indirection doesn't mean the users will have to wait too long for security patches.
about:config is a cat and mouse game, and I don't want to reconfigure my settings everytime Firefox updates. That's just hostile user design.
PSA (for the nth time): about:config is not a supported way of configuring Firefox, so if you tweak features with about:config, don't be surprised if those tweaks stop working without warning.