I like that professor. He might also have advised to limit words ending in ‘ing’ because they describe a state rather than an action. For example, “She was running down the road,” has less punch than, “She ran down the road.”
Also, avoid adverbs, he might say. If you have to modify a verb, then maybe the verb isn’t strong enough.
Ending sentences with a preposition was another. Still drives me crazy to see those from associates. Also the misuse of then/than, their/they’re, it’s/its, could care less (I guess you could), feel badly (Really? Don’t your hands works properly?) and the mispronounciation of asterisk. All that stuff was hammered home.
^^^^^^^SLIDE ALERT^^^^^^
I would argue that your examples may apply to some types of writing but not to others. Often expository writing can benefit from such pruning, but there are times when verbal flourishes enhance a reading experience.