I explain this in the instructions.
Yes, I agree it is best to have one step - unfortunately, you used python and I'm an html5 app developer. Also, I already have been using the these scripts for months and they only needed this wrapper script to make them into a single script.

The only value in the python script is the downloading of the android tools, plus it build one app that isn't from the 01.org web apps (iinm).

I suggest reducing the python script to simply installing the sdk - I've always done that manually since it has been a bit of a mystery where I should get it from, though that seems to be more organised lately.