There isn’t necessarily a leftist bogeyman behind every tree we encounter.
Yes, there are interests involved in undermining our culture; but in this article the usage is common and not incorrect. I’m an old lady and have heard and employed this usage all of my life, especially in contexts where the sex of a subject is unknown.
I humbly disagree. While in your experience the usage may have been common (I have never heard it until recent) it still remains incorrect. And yes, the present attempt to normalize its usage is an attempt to normalize the concept of non-binary.