By commercial, I mean commercial users using hobbyist spectrum. These would interfere with the hobbyist use. Instead, if you're a commercial user you go to your RSM or whatever and licence a bit of spectrum.

If you want to design and build something meshy, go for it. If you're licensed and obeying the rules, you can use the ham radio spectrum for your experimentation. I'd encourage that. But when you want to take it commercial by selling access, licence some spectrum to use for it and then you don't have to use callsigns, can use encryption, etc to your heart's content.

The purpose of the ham band allocations is to be a place where people can experiment with radio (or ragchew if that's more their thing), they're qualified to some degree so are less likely to interfere with others doing the same, and they're not being stomped on by companies using it as a space to do their ISP wireless data backhaul or whatever.

By "build a meshnet in the Ham radio spectrum and sell access" you're taking something that's a public good (with some conditions) that others had access to and reselling it, making it harder for others to do the same.