They aren't a matter of opinion though, there are defining characteristics accepted by a historied scholarly community that correspond with these words. There are ranges of perspectives as is common in any social science, so it is viewed as a 'softer' science compared to physics or chemistry but it is a science no less.

It may be common for criticial leftists to use these sort of terms flippantly, but that doesn't remove their meaning or usefulness in the larger discourse.

As you say, "thing they didn't say"

lol