And what exactly is ridiculous about it?

Reinforcement learning requires a well defined goal and a well defined way to quantitatively measure progress along that goal. In reality these don't exist without a hand of God guiding you. In the case of machine learning that hand of God is our own. Even given infinite processing power, you could not construct a reinforcement learning system that would mimic humanity's progress - it simply is a nonstarter due to the nature of reinforcement learning itself.

Conceptually, it's really not as hard as you make it seem. There are layers, but once you peel them away there's only one thing left, which all living things share: the drive to survive (maintain internal state parameters within a certain range by accessing nutrition, protection from environmental elements, security from other survival-seeking entities, reproduction to pass on genes, etc). No need to bring God/gods into it.

There's also no need to specifically mimic humanity's progress; that's just an accident of survival facilitated by opposable thumbs and language ability. We've already made machines with the base abilities, and emulated the drive (see evolutionary algorithms[0] for example). We just need to put it all together in a few units and let them "loose" to evolve on their own for a while. It took humans ~300,000 years to get where we are today; I'm positive that it'll take machines a small fraction of that. Nothing special.

[0] https://en.wikipedia.org/wiki/Evolutionary_algorithm

Very little, certainly approximately 0%, of what humanity has done has been driven by base survival instincts. You're describing the process to mimic a roach, not a human.

You do work, don't you (or at least are in school)? Do you do it for sheer fun? Or to be able to afford things that allow you to survive?

Even those who do something like art "for fun" do it because it sates an internal need (not all actions need to make sense, because the inherent randomness of evolution is messy and leaves artifacts). Though also the desire to create some form of legacy can be considered a kind of survival: to be remembered by others beyond one's own lifespan.