Nedarim 81a - Children of Talmidei Chachamim - Bracha on Torah

The gemara tries to understand why most talmidei chachamim aren't zocheh to sons who are talmidei chachamim, and offers different explanations:

1. R' Yosef - "so they shouldn't say Torah is inherited". Ran explains that the tendency is to expect the torah to be inherited so the sons of the talmidei chachamim often don't put in the effort necessary to master the torah. Rosh says that Hashem makes it more difficult for them to become talmidei chachmim so that it doesn't look like Torah is passed on by inheritance and would deter others from learning.

2. R' Shisha brei d'rav Idi - "so they shouldn't be arrogant on the tzibur". Ran explains that if the Torah remains in one family they will become arrogant and impose themeselves on the tzibur.

3. Mar Zutra - "because they express arrogance on the tzibur". The previous opinion was to prevent arrogance, but this opinion seems to understand it as a punishment to the talmidei chachamim for being arrogant on the tzibur (maharsha).

4. R' Ashi - "because they call people donkeys". Rashi explains they don't honor people properly. Maharsha explains that they consider others not having the inherent ability and genetic brainpower to become talmidei chachamim (like donkeys who don't have the potential), therefore they are punished by their own children not being talmidei chachamim which shows that that it is not inborn by nature, rather is only a result of hard work.

5. Ravina - "they don't make birchas hatorah". Ran explains in the name of Rabbeinu Yona (also rashi in baba metzia) that although they learned torah constantly, Hashem who understood their inner thoughts had to reveal that the beis hamikdash was destroyed because "Torah wasn't important enough to them so that it should be worthy of a bracha because they weren't learning lishma". The Beis Halevi (Parshas Mishpatim, and hakdama to teshuvos) explains that they considered learning only a hechsher mitzvah preparing them to perform mitzvos, but not a mitzvah in and of itself and therefore unworthy of a bracha. The Chasam Sofer (chiddushim) already offered this explanation many years before the Beis Halevi. He writes:

יש תורה לשם שמים ממש אך אין כוונתו אלא כדי לקיים המצות ולידע ההלכה איך יעשה המעשה, וכיון שכל עצמו של אותו העסק איננו אלא לקיים המצוה איננו עדיף מקיום המצוה גופיה דבעידנא דלא עסיק בה לא מגינא ולא מצלי. אך עיקר מצות עסק התורה הוא מצוה בפני עצמה להגות בה יומם ולילה ולהעמיק ולעיין בכל תוצאותיה ומובאיה כי עמקו מחשבותיה וכו' וזהו עוסק לשמה של תורה, לא על כוונה אחרת והיא המגינה ומצלי, ואז בשעת החורבן לא עסקו על זה האופן וכו'אך במה יודע איפה זאת אמר רב יהודה אמר רב שלא ברכו בתורה תחילה וכו' והשתא אי כל כוונת עסק התורה אינה אלא לעשות המצות א"כ אין למודה ועסקה גמר מצותה אין מברכין עליה, אבל המברך עליה מודה שכוונתו שמלבד קיום המצוה עוד העסק בעצמו מצוה

The Chasams sofer offers an alternate peshat that they weren't misbarech with Torah first, meaning they didn't glorify themselves as being experts in Torah, rather it became just another knowledge like other secular knowledge. This showed a lack of chashivus for Torah - [hence, the minhag to write "Rabbi Dr." rather than "Dr. Rabbi", v'dok].