The use of the word "SJW" is the same kind of social singalling that you attempted to criticize. It's a cheap insult, counter-productive to the discussion, and trivializes the real work on social justice that is necessary for humanity to grow up and become a mature civilization.

I actually agree with the main point you're making, that there are people who superficially attach themselves to social causes for selfish reasons. I am also skeptical when I hear about "serving the public", it's become a meaningless catch phrase by for those who seek to gain a leadership position in society.

And it may be tangentially relevant, that Google hiding the full URL in their brower was done in the name of "improving user experiece", when in fact it's more likely for a self-serving purpose. But that's not "SJW", it's a dark pattern used by corporations and political groups, on whichever side of the artificial divide.

So, I just want to point out that the word has been defined by the media you consume, that there are strings being pulled by the "anti-SJW" side also. It's best to not use that word, otherwise you risk discrediting any valid points you're making.