The ad-supported Internet is one of the few places where wealthy people and poor people are on equal footing, where children can still explore without parental permission, and adults can explore without constantly asking themselves "is this worth it?".
I imagine micropayments will be exactly the sort of problem people decry in Facebook's Free Basics, where large companies can afford to give access to their sites for free, while small website operators are forced to live in their walled garden or charge micropayments (and fade into obscurity).
I also think it's kind of weird how many people like the idea of micropayments for websites when we've seen firsthand what it did to gaming, and especially mobile gaming.
I too am hopeful for a better system that can replace advertising, but I don't think micropayments are that system.