Don't worry about it. It's an opinion. Agree or disagree with it. But to feel morally inferior because of someone else's opinion isn't an argument. It's revealing that you have issues with self esteem. If you want to put forth an argument about why he's wrong, or crossing a line, or making an unrealistic proposition that everyone everywhere should stop using a word or phrase, that's absolutely a valid response. But people making the claim of "virtue signalling" are not making an argument. They're making a baseless ad hominem attack.
I did ctrl+f searching for "opinion", "I believe", "I think", etc. I can't find any reference to "opinions".
I read the post as the author decribing facts and imparting instructions of what we should do ("It's time to do X", "The cargo cult metaphor should be avoided") because they believe their knowledge/opinions/morals/beliefs are better than mine, and somehow they can dictate what to do; how should I feel, what should I think.
Otherwise I am oppressing, contributing to oppress, perpetuating something, [insert other accusations].
As in the past 15 years. It's enough already.
The real question is why the author is doing this? Is it ego? Money? Clicks? Pure and true altruism?
And here "virtue signalling" comes as a possible valid answer too.
The context is a personal blog. You don't have to say the word "opinion" explicitly. If it's on your blog, it's your opinion.
The problem with saying it's virtue signaling is that when you resort to ad hominem attacks, you're conceding the argument. Attacking character concedes the argument being made. Well I don't concede. I have a good argument against it. My argument is that nobody cares about the etymology or morality of a word. They care about its meaning and context. People don't learn language by reading etymologies. Nobody cares one way or the other about the morality of the first person who said it or popularized it especially if it happened a hundred years ago. We don't need to look up the etymology of every word or phrase before using it, and asking people to do that is unrealistic and unreasonable.
Is it virtue signaling? I don't know, and I don't care. His character doesn't matter to me. It doesn't affect whether or not his idea is a good one. It's a bad idea, and leave it there.