It seems you're expecting the impossible without realising it.All software is buggy and incomplete when first developed. It takes time, testing and improving to become stable and feature complete. In the closed source world you have whatever the developers choose to give you because they have to get something out on sale to start making money. In the FOSS world you have the choice. You can either have the very latest knowing it's buggy, incomplete etc or wait to have the better tested and more feature developed stable release. They are not the same thing. This is why distros like Debian have a Stable version; the packages are kinda old but they are meant to be stable and solid. Others like Fedora or Debian Sid got the opposite end of the spectrum and give you cool new features, the trade-off being it's not that well tested yet.
I don't like the latest stuff, that's why I don't use a distro based on that philosophy. I appreciate those who do, it's how I see those features months down the line when they are better tested. Choose your distro and versions of packages according to your preferences.
I note you state quite proudly that Ubuntu 11.10 has the Gnome Shell option. It does, it's just as buggy.
As others have pointed out, this is a transition time between Gnome 2 and Gnome 3, with others like Unity coming into the mix. It means not only the environments, but the applications themselves changing their toolkits. For a while, the Gnome tree will be messy, confused and buggy. It's a similar mess that KDE went through with the switch from 3.5 to 4. It takes a few releases to start to nail things down. In the meantime, some distros follow the bleeding edge, others hold out with older but stable technology, and some users switch platforms altogether.
The Mint team have held off from making the Unity / Gnome Shell decision until the dust settled more, saw that neither was a clear winner and tried to do something admirable and adventurous in mimicing the look of the traditional Gnome 2 desktop as much as possible with Gnome 3. Of course it's gonna be buggy right now. Even if Canonical or RedHat (companies with way more paid resources to devote to it) took the Mint approach, it'd still be buggy right now. It's also a RC release. Usually this means "something pretty close to final quality" with Mint. With Mint 12 and the vast amount of changes made, it appears not to be such high quality this time.
As others have also pointed out, there is no rush for people to upgrade every 6 months. There are LTS editions or even the rolling Debian based editions so you don't have to. If you value stability like I do, choose your distro accordingly. If you value the latest and greatest, expect that it's gonna break at times, and help the teams out by reporting bugs.