I think it's you who has a very narrow vision of what a hackathon can be. Hackathons can both be about developing your programming skills or coming up with, then presenting new and interesting ideas.

In a sense, the latter is kind of about "landing VC deals", but replace VC with possibly a different audience.

I think this narrowness of mindset is more notable in the last paragraph: "...you want to discover yourself, and maybe some other people, not what a robot can do." In my perspective, what I think OP is saying, and I can personally see, is not about what a robot can do (at least no more than when experimenting with a different language/framework/library/etc.), but how far can you shape and accomplish your idea into reality using AI.