We don't want just the fruits of everyone's hobbyist weekend warrior free-time. We want it to be profitable to make the stuff we want to consume so that we get better content than hobby/charity content.
Also, most things aren't hobbyist cheap. Even in the era you're looking upon nostalgically, consider message boards. You'd either use a freemium solution like Proboards/Ezboard or you'd pay for hosting which could cost you $100+/mo if your forum was popular.
I have a feeling every time people talk about the old hobbyist internet, they're talking about brochure Angelfire websites they themselves never spent all that much time on. Most people want better content than that just like most people want to watch Breaking Bad and Game of Thrones, not hobbyists on Youtube.
Yet these threads always sound like "remember the good ol days before Breaking Bad when it was just hobbyist vlogs on Youtube? ahh, those were the days even though I didn't watch vlogs, they were boring."
Maybe things were different before the AOL era back when there was almost nothing online that we want to do online today, but I'm in my 30s and first got internet in the 90s with AOL and "profit motives" were always the driving force for why there were compelling things to do online, like playing Age of Empires multiplayer through MSN's Internet Gaming Zone platform in 1997.