2) The problem is not unique to English. We use the term "double
entendre" which taken from French and retains distinctively French
pronunciation. In some languages and cultures, constructing
elaborately ambiguous expressions is considered an erudite art
form.
3) The bible says "Judge not, that ye be not judged" but in fact
everybody likes to be judged, so long as the judgment goes their
way.
4) Words such as criticism and sanction are extreme cases, open
to diametrically opposite interpretation. In light of item (3),
this is unsurprising. We could rename "critical thinking" to
"judgmental thinking" but that would not be an improvement.
5) There is such a thing as an idiomatic expression. The meaning
of a word depends on context. The "critical angle" does not mean
the censorious angle; it just doesn't.
Sometimes criticism is constructive, and sometimes not. Giving
constructive criticism is a complex task, requiring judgment and
skill. Changing the terminology will not help in this case. We
have bigger fish to fry.