Because AI is a massive waste of resources that has yet to prove (to me at least) that it can provide any kind of real benefit to humanity that couldn't be better provided by another, less resource intensive means. Advocating for 'common' AI use is absurd in the face of the amount of energy and other resources consumed by that usage, especially in the face of a looming climate crises being exacerbated by excesses like this.
LLMs may have valid uses, I doubt it, but they may. Using it to make memes and generate answers of questionable veracity to questions that would be better resolved with a Google search is just dumb.