> It's easier to throttle people if you have to use an account to access the information.

That's not true in the slightest. I can create as many accounts as I can have email addresses, and I can have as many email addresses as I want.

Robust throttling _requires_ an alternative throttling mechanism that works independent of account information, otherwise I can round-robin between accounts to bypass all throttling.

If you're gonna have that anyway, we're back to "no technical need for accounts".