In any discipline motive is important but that also means that as one progresses, one can adjust the motive. A student who begins with the worse motive may adjust himself/herself as the progress comes. Here is an interview, take notice how the teacher began with the motive to be famous for punching coconuts.
What a motive?
For inSelf Yoga™ that is ridiculous. But wait a minute, even though this yoga concerns what is in the psyche and it is not concerned with what is exterior to the psyche, still maybe, just maybe, a student may have bad or silly motives for a start.