Because casual two-way communication is only thing that Nostr is better at than the alternative options.

If you are interested in high effort monologues then ActivityPub is already perfect. There's no need for the people consuming content to make a real account. They could browse the Fediverse and when a creator posts something the person likes, they can visit the creator's profile, copy and paste the address of their crypto wallet, and send whatever they want.

Shoot, if the other person is already putting in the effort to create good info, tools, and entertainment then they could drop the microblogging protocol entirely. They could just start a blog and you can find their posts using a search engine/web crawler.

Obviously people are free to use worse tools and create a worse experience for themselves and the people they associate with. The biggest reason I'm talking about this topic at all is because I figured people would want to dispute the conclusion I've come to, and because if so, I'm interested in talking with them.