Because of the word "于" here, I have a hard time understanding this sentence.
In my attempt to understand it, I've searched for a few similar sentences to be compared. Unfortunately, the word "于" seems to have different meanings in each sentence (I might be wrong).
I assume in these it means 'by'. (1. Professionals state that immigrants are vexed because they felt they're not accepted by the society? 2. Geniuses/highbrows aren't tolerated by the world?)
I feel the "于" in this sentence is the most similar with the one in my original sentence, so I'm not sure about its meaning.
So, my questions are:
What does the "于" in my original sentence mean?
Is "于" necessary when I used "不容"?
Does the usage of "于" always turn the sentence into passive voices (the translations) as it does in example 1 and 2?