If you look at your reflection in water, it may very well move even though you don't. Similarly, you don't need agency or reasoning to create something new, random selection from a large number of combinations is enough, correct horse battery staple.
Of course random new things are typically bad. The article is essentially proposing to generate lots of them anyway and try to filter for only the best ones.
I agree that brute forcing is a method and how nature does it. The problem would still be the same, how would it or other LLMs know if the idea is novel and interesting?
Given access to unlimited data, LLMs likely could spot novel trends that we cant but still cant judge the value of creating something unique that it has never encountered before.
We're looking at our reflection and asking ourselves why it isn't moving when we don't