sometimes libraries become incompatible with future versions of the operating system
Or it becomes time to abandon support for older versions of android and make libraries that only work with newer versions.
This is the case with my PreferenceExtras library.
PreferencesExtras uses a PreferenceFragment so only works on Honeycomb and newer.
The same logic applies to the b4a GoogleMaps library - it uses a MapFragment so is only compatible with Honeycomb and newer.
I'm sure both libraries could have been written using additonal compatibility libraries that add Fragment support to older versions of android.
But look at the statistics that show what versions of android people are currently using:
http://developer.android.com/about/dashboards/index.html
Just
3.6% of users are using a version older than Honeycomb.
Is it worth the time and effort to make libraries compatible with such a small percentage of users?