If I feel I'm doing a disservice to the person by not speaking up, but still stay silent because I don't want to be confrontational or harsh, I don't think I'm being kind to the person. I'm only protecting the relation or myself, as I don't have the tools or a path to convey helpful information while making clear I'm having the person's good in mind.

I see it as a failure in communication (it usually can be blamed on both parties), and clearly not a character quality.