I'm fond of linguistic bugbears, and have actually sent that same article to people before :D But what you're missing is that the less/fewer debate is over their use as adjectives, and TFA's title uses "less" as an adverb. It's asking for AI agents to be less human, not for them to be fewer in number. Swapping it to "fewer" would make the title's meaning no longer match the article.

Now please sit a moment and reflect on what you've done. :P