Earlier quoted context omitted.
I experienced the same thing with English teachers. But I had a friend point out that Hemingway (whom we both adored) wrote sentences that were 7 words shorter than normal. Writing short punchy sentences without a single spare word. Steinbeck wrote that way and so did Elmore Leonard. Leonard said he'd get down a first draft and then go back a second time taking words out that weren't necessary. https://www.litcharts.…
One can idolize Hemingway to a fault. Removing the unnecessary is largely what a second draft is for , no matter who's doing the work; concision is a virtue, but to pursue concision above all else risks erring into insufficiency and rendering oneself unable to write in one's own style and voice, rather than in an emulation of someone else's. Voice elevates an informative essay from a dry recitation of facts, offering…
I aspired to concision because I believed I wasn't an interesting person and didn't deserve any attention outside of the little I'm able to grab, so I kept my writing pithy in the hopes that I wouldn't have to "take up too much of anyone's time/attention".
Unfortunately, too much concision can lead to short pieces that are tiring to read -- your brain has to work harder to fill in the gaps. Sometimes "unnecessary" words are needed to help the reader feel more comfortable. Not everyone is an engineer or a technocrat. Parsimony isn't always a virtue.
There's is a place for concision, but I now believe concision is the wrong goal to aim for. Often the real goal is to create an emotional connection, and if it takes a few more words to achieve it (without belaboring the subject), so be it.
People -- often teachers -- think good writing is solely about effective communication -- to me, there has never been a wronger conclusion than this.