I understand that it has uses, but why force me to create an account just to send you money?
You don't have to do that, you can pay through the invoice in email by using a card. I'm not sure if it's the same if you are ordering online.
In this case, the vendor isn't invoicing me, they're passing a request to paypal to collect $X.
I realize that's a thin line, but the only piece of information paypal gets is collect money and return it to the vendor. They don't know why or for what. When I attempt to pay it, it only gives me the option to create an account so I can pay it.
Usually, there's "Pay as a guest," but for some reason that's missing for this one.