API rate limits, the polite way to say developers please fuck off

I just received e-mail from Evernote saying they are going on with their API rate limits. Twitter enabled API rate limits recently causing a lot of connection to fail or vanish because they weren’t able to cope with the limits.

Wouldn’t it be a better idea to actually charge for API access?

If you really want to have the ecosystem under control, why don’t you just ask developers to pay for using the service?

This way if they are successful you’re successful too.

Better idea than to just punish everyone for using your API.