Is the lesson that since professors are "less free" than everyone else, they criticize everyone else out of bitterness? Or is it that since they're so specialized and able to make a living only in their specialty, they don't need to practise good judgement outside their discipline? Is it that they live in an ivory tower and don't know the difference between theory and practise? What does that quote mean?

...

Maybe they "abdicate their freedom" when they have to teach students and battle administration. I seriously don't know what that quote means.

E.g.: If you focus too much on engineering, you stop being able to see value in other aspect of life, such as philosophy.

De Beauvoir describes a couple of states of freedom of mind: 1. Children who believe in what they're told and don't think about their freedom 2. The serious man who chose a goal in life and do not think about their freedom (which the quote is about) 3. Nihilists who realize they're free but chose to do nothing 4. Adventurers who accept their freedom, but chose no precise goals 5. Passionate men who choose a goal according to their freedom and show no concerns for others 6. Genuine freedom (freedom + goal + concerns for others freedom)

(Also, this feels eerily similar to the first time I realized "Oh, going and reading the source of $LIBRARY is an option if the docs are too vague.")

The specialised activity provides high reward, the generalised little, or at least less.

We need to define flight here: "a brilliant, imaginative, or unrestrained exercise or display" [1]. So he fulfills himself as a a brilliant, imaginative, or unrestrained exercise or display. He toots his own horn, to promote oneself; to boast or brag; to tout oneself [2].

What does the quote mean?

They (some doctors and professors in this quote) have abdicated their freedom to their discipline or interest. They see all things through the single lens of their discipline, and all things outside of it as trite, "stupid", something not to think on at all or to think of only in how it relates to their specialty.

Take the result of Zuckerberg's "need" to monetizing Facebook. This has dire consequences on peoples security, and even peoples personal sanity. To Zuckerberg these things are dealt with in a way "lacking in sensitivity, intelligence, and humanity", all that matters is Facebook's bottom line. Further on in Simone de Beauvoir's Ethics of Ambiguity she quotes "The rest of the world is a faceless desert. Here again one sees how such a choice is immediately confirmed. If there is being only, for example, in the form of the Army, how could the military man wish for anything else than to multiply barracks and maneuvers?"

The overall idea being that people highly specialized and competent in one area make the logical fallacy of arguing from authority (themselves being the authority they are arguing from) and put forth the most mundane, lacking in nuance "ordinary values" in areas that they have little understanding, haven't researched and aren't really interested in.

1. https://www.merriam-webster.com/dictionary/flight definition 5

2. https://en.wiktionary.org/wiki/toot_one%27s_own_horn

In which case, why specific people are more intelligent than others, and whether that intelligencee is highly general (rare) or more specific (common, almost painfully or absurdly so at times), and why, is a fascinating question.

Beauvoir and Proust suggest that the mechanism is technique rather than a more general capacity, and hence focused on specific capabilities. That is, a method effective at crossing some specific divides, but not providing a deeper vision or reach, or higher vantage, generally. That last visualising a conceptual landscape as having peaks, valleys, and barriers (walls or chasms) to be crosssed.

Technique providing bridging capacity, but not view-from-a-peak.