Unity's come a long way since it's rather embarrassing first appearance, and that's a good thing Ubuntu. While I'm sure arguments over whether it's good or bad will rage on for years, the one truth about it is that it is an Application-Centric shell. AC shells are becoming the norm in the OS front, as seen by Unity, iOS, Andriod and the up-and-coming Windows 8 Metro. From a usability standpoint, they make perfect sense - they're very, very easy to use for someone who knows little to nothing about computers.
Therein is the problem for the power-user. Power users (Network admins, coders, computer enthusiasts/expects, etc.) tend to do a lot of things at once, and an AC shell is terrible for trying to actually do serious work with a computer. Power-users tend to migrate toward Task-Centric shells where active software is displayed on a task bar of some sort with applications contained in their own windows. Again, this makes sense given the type of user.
What does not make sense is Ubuntu's lack of flexibility in regards to the shell. While it caters nicely to the novice user, a power-user has little choice unless he/she wants to go to the trouble of installing an alternate shell that is more Task-Centric in nature.
I personally switched from Ubuntu to Mint back in 2009, at the time largely because Mint was a much more polished distribution. Now, Mint offers the extra perk of a shell that gives the user a choice as to how Application or Task Centric they want their environment to be. Their extensions to Gnome 3 initially allowed this with the Mint 12 release, and later their Cinnamon shell (a fork of Gnome 3) took it a step further. This is the sort of flexibility I wish Ubuntu had, but it seems they're content to stick with Unity and the base Gnome 3, and in the last year that's cost them a huge number of power-users, and likely will continue to do so.