It can be pretty treacherous for consumers though (part of why Minefold is great, by investing in building a platform they've demonstrated they have commitment to the business) because inevitably most teenagers don't understand the commitment they're making to their customers and things frequently fall apart. I can't count the amount of problems hosts falling apart has caused me, I had to make a concious effort to exclude it from my life about 6 months ago after a kid threatened to drive to my apartment and beat me up.
[1] Most are relatively small but there are quite a few teenage run Minecraft hosts supporting thousands of customers. The biggest Minecraft hosts are "proper businesses" though, with companies like Multiplay hosting ~15k Minecraft servers.
[2] I assume everyone here had their fun times running a web host at some point in their internet career.