Comment 3 for bug 420703

Mark , this confusion seems to be since you have misunderstood the install button and misread the labels.
In reply to your points:
1. The install does install properly packaged themes, so removal of the button is not a solution. And the install button asks to install themes "Packages" not .theme files. [ex: .tar.gz] and there are several formats these themes can come in.
2. Ubuntu themes can already be installed from synaptic as > community themes. Granted , these are few . And there is no repository for the themes that gnome-look.org or any other site has. But the idea is nice.
3. The problem arises only when the themes are not properly packaged. And only when you are trying to modify the default setup. So this is not a papercut.

Yes, this is a bigger problem , Hence I'v suggested you add your comments to the Software Store comments page.
Thanks.

PS: Maybe you havent realized this, theme packages can also be dragged and dropped into the appearances window to install them.