Trying to specify what purposes you're allowed to use your connection for seems like a losing game, and is basically the root of the whole problem. Just what is "personal use"? How exactly are they going to enforce that?

Instead of trying to separate different "kinds" of usage, they should just separate different amounts and traffic patterns. Want a connection you can saturate 24/7? Pay more. Want something suitable for "personal use"? It's going to have some sort of cap.

That's how most products I buy are sold, whether physical products or services. The electric company doesn't sell me electricity "for personal use". The water company doesn't care if I'm taking a shower or selling car wash services. The grocery store treats me exactly the same whether I'm buying supplies to cook tonight's family dinner or supplies to make sandwiches I'm going to sell. I fill up my personal car next to commercial trucks at the gas station, and there's no "personal/commercial" option at the pump.

The real problem, in my opinion, is a bizarre prevailing environment where "unlimited" service is somehow expected of ISPs. Attempts to actually charge for use encounter huge resistance from the tech community. But they can't actually provide unlimited service at the price they charge, so they end up with a ton of weird rules to limit service instead of just charging heavy users more.

Charge a reasonable price per gigabyte, and problem solved. People who want to saturate their connection all day can do so, and will pay accordingly. Light users pay less. It works out for almost every other product and service in the world!