Why does Android 3.x have no market share? According to the Android Developer Dashboard, the market share of Android 3.2 is only 0.1%, and no other 3.x version has even as much as that.  Versions 2.x and 4.x have all the market share.

Can someone please explain why there's a whole major version of Android that is apparently unused, while the previous and the next major versions are in wide use?  Was 3.x quickly replaced by 4 and all devices forced to upgrade?  What would have made 3.x so bad that no one uses it?
Honeycomb was a tablet-only version of the OS
It was only ever released for a few devices
The source code was never released not released until the source for Ice Cream Sandwich was available, and even then the Android devs noted that 3.x source was not complete
It never had much in the way of market share


See also:


What percentage of devices have each of the Android versions?
Is Android 3.0 Honeycomb only for tablets?