I'm pretty sure those users are a vocal minority.
Personally I loved Unity. The only thing I disliked about Unity and Ubuntu's UI in general is the lack of configuration options, having to install extra buggy configuration managers to do really basic stuff, like turning Caps Lock into Ctrl. But that's a problem with the whole Gnome ecosystem and not Unity.
And Unity I loved, because it has pretty good keyboard shortcuts, is space efficient and generally worked for me just fine out of the box.
Going back to why Canonical dropped it, I'm pretty sure that's because they are giving up on the Linux desktop in general.
As for the comparison with Apple, dude, you're comparing David and Goliath, except this is the real world.