Does anybody know why the teams behind the Unity and Gnome 3 Desktop Environments chose not to include a program for easily configuring such trivial aspects of the OS as font size and instead require fiddling with the gnome configuration or an external tool to be installed (such as the gnome tweak tool)? Why was this design decision made? Incidentally, given the above, how does Canonical expect Ubuntu to be adopted by the average user?

I am not an average user but I would think a desktop environment that aims to be easy to use and adopted by the masses - like Unity - would include a comprehensive configuration tool as an intricate part of it.

I am myself a user of XFCE (since 4.6) and never used Gnome Shell or Unity but I did try the latter a couple of weeks ago out of curiosity. I suppose I just couldn't believe that a company (Canonical) that aims to bring a FOSS OS to the masses as well as now targeting the tablet and smartphone market didn't even think to allow its DE to be easily configurable. Frankly, I find it beyond belief.

Technical users can make informed decisions and choose the DE (and even distro) that suits them best but the same can't be said of the average user who wants something that just works and doesn't introduce radically new paradigms or feels crippled.