The really ironic thing is that this article demonstrates the correct, purposeful human usage of these stock phrases and is getting skewered for it because it superficially sounds like AI. It's not exemplifying what it's criticizing, it's exemplifying the exact reverse of what it's criticizing.
"It's not X, it's Y" is for when you know your reader will think X, and you want them to understand the difference between the X they are expecting and the Y that is actually the case.
Here are the two "not just" passages in the article:
> Driven by this discrepancy, I built a simple tracking script. It was not a sophisticated piece of software, just a tool designed to observe how "users" actually interacted with the website. I was not just counting clicks; I was watching behavior.
> The bots operating today are disturbingly good. They are not just hitting your site and leaving; they are programmed to mimic engagement, making your marketing ROI calculations dangerously inaccurate. I began to categorize them.
Both of these passages are using the "not just X, but Y" trope in a purposeful, meaningful way, anticipating what a typical audience member might assume and signaling for them to adjust their expectation. Not just trying to maximize the usage of the trope with random non-sequitur values of X and Y, as GPT does.
(Oh dear, I just said it too.)
It would be interesting to assemble a corpus of meaningful human text with superficial use of AI tropes, put it side-by-side with true AI slop, and see who can tell the difference. I suspect that, in the coming years, this will be a test posed in higher education and job interviews.