I'm a software engineer and it's my favorite GUI available for Linux. I've used all the hip things like Xmonad, dwm (for a long time), XFCE (for a very long time), Gnome 2 and 3, KDE 4 and 5, i3 (which I still like a lot), et cetera.

I still prefer Unity nowadays. It's simple, it's fast and stable (at least for me), and it reminds me of OS X (which I also like).

Everyone who runs Linux at my job uses it. No one had to be taught how to use it. No one has had any issues with it or complains about it. It just gets the job done.

I totally get that not everyone likes it, but Canonical is targeting a general audience and I think they're doing a good job. If you don't like it, just apt-get something else. It doesn't need to be super customizable and cater to everyone. Let them focus on their core features for their primary audience.