I'm against -Isms.
My entry into the crusade was occasioned by Thomas Alexander, who despises them. I will tell you my reasons why in a case example, something I'm working on.
I plan to present a counter-argument to a recent author's thesis. My primary critique can be simplified to this: the author claims that these folks are for this -ism, which is in contradiction with these other -isms, but the author equivocates multiple times for every -ism introduced. The author is not just wrong, but erroneously conflates so many concepts that I question whether the work is disingenuous.
I see this all the time, especially between cross-tradition work. (That's another post--my fervent insistence that philosophers recognize traditions and the implications of philosophy being tradition-bound; denial is like refusing to admit one has a mother.) Frequently in other cases, I will engage in cross-tradition conversations that constantly run afoul of terminology, but none so pernicious as the "umbrella terms," especially -isms. Using these terms is not per se bad, but using them without being able to define them and distinguish their varied denotations--all too common in my experience--is a pernicious unthinking.