I grew up a Seventh-Day Adventist. I was a preacher’s kid. I knew dozens of clergy. Almost all of them said they felt a divine call to become a pastor.
By contrast, I don’t know any rabbis who felt a divine call to be a rabbi. Instead, it seems to me that for most of them, the rabbinic position was the one most congenial to their talents. It was the easiest and most enjoyable way for them to earn a living and to advance in the world.
It strikes me that most of the public faces of Judaism in the world today, including most of the gadolim Yisrael, chose to become rabbis because that was their best opportunity for feeling like a big shot. Just as I’ll do most anything for attention, so too the great rabbis became rabbis principally because that’s the endeavor where they get the most positive reinforcement.
Just as a plant grows toward the light, so too most of us choose things based on the rewards that the world gives us for our choices. Life has a way of sorting us out and channeling us in directions where we have expertise.
Some rabbis were truly saintly. The Chofetz Chaim and the Chazon Ish come to mind. I think these guys really wanted to be of service. For most of the rest of the great rabbis, that position afforded them the most chance for honor.
Think about Rabbi J.B. Soloveitchik. He did not want R. Yechiel Yaakov Weinberg to come to Yeshiva University after the Holocaust because that would’ve taken away from JB’s honor. And Rabbi Weinberg did not want to go to anywhere where he would not be the number one gadol.
Almost every great rabbi has a great ego to rival that of any Hollywood star.