Compared to Windows, iPhone, and Android. Android has the worst tooling environment of them all. You would expect a big software company like Google to know better, but you'd be mistaken.
All others provide you a native simulator that you can use to ease development ( Windows even provided one for Windows Phone). Android provides an emulator that gobbles up RAM and is painfully slow to use. Most people just prefer to use their local device instead.
Other platforms provide you their own IDE tailor-made for development. Google just took IntelliJ and made some changes it.
Edit: Another point is compile times. Compile times for Android are just atrocious. While Windows and iOS compile quickly in a few seconds and allow you to fast deploy, Android is painfully slow taking over a couple of minutes for compilation.
All others provide you a native simulator that you can use to ease development ( Windows even provided one for Windows Phone). Android provides an emulator that gobbles up RAM and is painfully slow to use. Most people just prefer to use their local device instead.
Other platforms provide you their own IDE tailor-made for development. Google just took IntelliJ and made some changes it.
Edit: Another point is compile times. Compile times for Android are just atrocious. While Windows and iOS compile quickly in a few seconds and allow you to fast deploy, Android is painfully slow taking over a couple of minutes for compilation.