As thp says in his blog article about PyOtherSide : So it seems PyOtherSide is lighter to install and load than PyQt/PySide. But developers want and need freedom and options. Let remember that many Python mobile developers have only some hours per week or month to develop as a hobby, so if there are tools easier to migrate (from Maemo/MeeGo/PC) to Sailfish, they will want them. Some of the Python softwares could be developed in C/C++, but then it would take more developing time and some would not be finished at all. And please, stop saying mobile Python developers are lazy. They contributed and will contribute with a lot of free and open source softwares for Maemo, MeeGo, Sailfish, etc.