It doesn't matter where an idea like "slut shaming" comes from, what matters is the negative feeling associated with being "slut shamed" resonates with a lot of people.
To take the analogy seriously (not advisable), it's like saying, "money isn't valuable if it's laundered". Absurd and wrong; sure, laundered money is bad, but it's the laundering, not the money, that's the problem. If we stopped the laundering, the "money" is still worth what it's worth, but does the author suggest the people who put names to the feelings many people are experiencing should stop? No. The author suggests the ideas are "nonsensical" and doesn't elaborate.
It's just strange to me that the left has come to own the defense of minorities, but it's a narrative that both sides have totally bought into, and zealously attack/defend.
Why is it "liberal" to care about someone's feelings?!