"This is bullshit" in the source code comments makes your TA laugh and is appropriate at school, but at work the execs and customers who get source access don't think its funny especially if you make fun of the customer. Some of the most trivial basic management skills that often aren't applied in school at all, but are applied at work, like compliment in public and blame in private. At school in algo class culturally all that matters is getting the best O(n) behavior because thats kind of the point of the class, possibly work culture is not so interested especially if there is a basic physics reason or financial regulation reason n can never exceed 3. (edited to emphasize its not that these specific examples were right or wrong, but that it wasn't "gotten" that they were wrong at that work team, but the new guy genuinely, incorrectly, thought it was a cultural fit)
Its not so much being right or wrong in an absolute sense the problem is thinking they know the culture better than they do leading to innocent inaccurate behavior decisions.
The worst intern-specific train wrecks I've seen involve the intern's keeper(s) not having an accurate view of the interns abilities.
The worst young-person-specific train wrecks I've seen involve young office employees having an incorrectly high assessment of their office culture knowledge. Nothing I've seen on TV and movies about office culture is useful or enlightening. Culture, as in local traditions for interpersonal relations and local shared group priorities.