I think your concepts are correct for the great majority.
My witnessing and pioneering were done to prove that I was worth something.
I felt worthless because I was a homosexual. I realized for sure that I was homosexual when I was about 13. I was racked with guilt. I auxiliary pioneered every summer. Pioneered after high school and eventually went to Bethel.
I was dismissed from Bethel after admitting I was a homosexual (still a virgin). More pioneering followed with even more intense fervor. I had to prove that I was worthy of being a Jehovah's Witness.
My goal in service was strictly to get Bible Studies. At one time I had 7 Bible Studies going at one time. Once I had 4 Bible Studies at the Hall at the same time.
But, the pioneers around me were pretty much going through the motions. It was tough. Most of my good pioneer time was put in with my mother, who would go out with me anytime to help me get my hours.
She truly enjoys field service. She lights up at the chance of talking about the Bible to people. I think she would rather go in service than do anything else. I agree she is certainly the exception to the rule. But then, to me, she represents what is really meant by being one of Jehovah's Witnesses. She wants human suffering to end with all her heart and she wants to help people.
Obviously I admire her loving Christian spirit.