This is a straw man position. Who is saying AI is doomed? There were previous winters but the technology kept improving. What people are doubting is all the current hype around it. Stuff like AGI and the singularity being right around the corner with fully automated societies and robots dong all your chores for you.

Rather than it being presented as productivity tool for enhancing human labor and activity, it's presented as an eventual god that will radically transform the rules of economics and everything else, and thus it needs to be forced into everything. That's absurd hype and with it all the absurd VC funding and valuation. Thus it's seen as a huge financial bubble.