Linus uses KDE, IIRC ;-) I don't really know
anybody who liked Unity (what's shipped by default on Ubuntu) out of the box. I know people who have learned to like it, so I suppose it's an acquired taste.
I actually like Gnome 3 because it is highly configurable for a programmer (plugins are really, really easy to write). But, in the end, I don't like all the Gnome infrastructure -- especially they really broke internationalised input for a long time and pretty much forced me to change.
My wife uses KDE and absolutely loves it. I had previously introduced her to Gnome 3, which she didn't like and Cinnamon, which she was pretty neutral about. She was originally a non-computer user -- she had only ever used a cell phone for her whole life if you can believe it.
I eventually migrated to XMonad and I don't think I will ever change to a more integrated desktop environment.
Free software is about freedom. It's freedom to use your computer how you see fit. It's freedom to write whatever software you want, or to tweak it, or to fix bugs. It's freedom to help other people by writing software, or tweaking it or fixing bugs.
The idea of having some coordinated effort that makes decisions for everybody and provides a lowest common denominator is appealing for a lot of reasons. Probably that's what it takes to compete with the vendors who see the computer as an integrated consumer good -- a black box that is highly targeted to a particular market.
As a user of free software who enjoys his freedom, penetrating the mass market, but removing choice is not something I look forward to. I think some people have this idea that Linux needs to have mass market appeal to be successful. I am not one of those. I'm happy if more people want to enjoy software freedom, but I could care less about Linux market penetration on the desktop.
But anyway, if you are interested, I would give KDE a shot. Personally, I find it over complicated, but it has some really compelling features if you're into that kind of thing.