I got into instructing because there were no real jobs around.
I have thoroughly enjoyed it, and have been an A-category instructor (similar to Grade 1) for seven going on eight years.
But that said, people who knew me well (parents), said that I would make a good teacher before I ever went into it.
So I think motivation is less important than many here have said, as a professional will do the job carefully regardless of preference.
Character and natural inclination are very important.
Good luck either way.
O8