Our Gemara on this daf relates two incidents about people who work for a living, which actually represent contradictory ideas. 

On Amud Aleph we learned of two sages, Rabbi Yochanan and Ilfa. They both were in extreme poverty, and at a crisis point, pondered leaving torah study in order to engage in business. Ilfa decides to leave, while Rabbi Yochanan continues to engage in Torah study, obviously with great sacrifice. Years later, we find out that Rabbi Yochanan was chosen to head the Academy over Ilfa. Now, Ilfa was no slouch and despite his engaging in business continued to study Torah extensively. In fact, he protested, and challenged anybody to ask him any question to see if they could stop him, to prove that his Torah knowledge was equal or greater to Rabbi Yochanan. Despite this, he did not merit the position and was not chosen.

There is no explanation offered, but we must assume that ultimately Rabbi Yochanan’s Focus, availability, and possibly even  his knowledge was still considered greater.

Then on Amud Beis we find out that a professional Bloodletter, Abba Umana, which we might consider a physician, received daily greetings from the heavenly Yeshiva. Much to Abaye and Rava’s dismay, they would receive greetings much less frequently. That is, weekly or annually, respectively. 

The Gemara goes on to offer an explanation for why Abba Umana merited this special attention. Let us keep in mind, this was not merely some kind of blessings, but actual greetings from the heavenly Yeshiva. This would seem to confer a particular honor in regard to the Torah study onto Abba Umana, despite him being a professional, and in contradistinction to Abaye and Rava.

The Gemara enumerates a number of meritorious practices that Abba Umana engaged in:

1. He was modest with his female and male patients
2. He would take his fee anonymously so that those who cannot pay were not embarrassed
3. Not only would he treat Torah scholars for free but he would also give them money to purchase food afterwards to recover.
4. He was unusual in his ability to be humble and judge others favorably, despite circumstances heavily slanted toward guilt of the other party.

So, how do we understand that Abba Umana, who is not even noted as a particular Sage, receives greetings from the heavenly yeshiva far in excess of the great sages Abaye and Rava, but Ilfa who presents as learned as Rabbi Yochanan, does not qualify to become Rosh Yeshiva?

I have two possible answers. First, perhaps the rabbis had their reasons why in this material world they felt a full-time Talmid Chacham was more appropriate for leadership of the Yeshiva. After all, most people would not be able to achieve what Ilfa achieved by being a “Earner-learner”. Thus, simply put, the talmidim needed a more appropriate role model. On the other hand, the heavenly Yeshiva can operate according to different principles and represent the absolute truth. 

Another possible answer is that the professions were different. Ilfa was a businessman. His daily work did not entail chessed. Furthermore, we hear nothing about how he conducted himself or if he did unusually exemplary acts that created a kiddush Hashem. On the other hand, Abba Umana clearly performed excessive acts of kindness in the course of everyday work. Perhaps that was the clincher.