I could harm your service by making too many API-key signed, OAuth-signed requests too. I could harm your service by hitting your website a lot too. We have ways of dealing with people who intentionally or unintentionally launch the equivalent of denial of service attacks: you block their IPs and move on. There's no need to have a special magical way of doing it with an API.
The point is the whole concept of an API should be unnecessary. We have a way of saying where data is: URLs. We have a way of specifying what format the client wants it in: content negotiation (Accept headers). We have a way of retrieving that data: HTTP GET. There's a reason why BugMeNot exists for websites. API keys are basically pointless registration pages for access to the same data that is being published on the web.
As for the code samples: if there's little more needed than "here's the URL of our data", I don't need a code sample. I only need a code sample when it's been made ridiculously over-complicated.
(My favourite API recently: clockworksms.com - all of the other SMS providers I've looked at want me to talk to some salesman and/or read complicated docs. Clockwork just let me send an HTTPS POST message. They have an API key, sure, but they required only an email address to get it. And I can pay for credits with PayPal. Ridiculously simple. I like.)
As for arrogancy? Guilty as charged. I'll say in my defence that it's more that the data I wanted to retrieve from the service in question (which I won't name) was exceptionally simple, had no commercial value in itself, but would send referrals to the site that they could monetise (and there's no affiliate scheme, I wasn't gonna profit off this). There literally is no business reason to lock that kind of API down. It's just cargo-cult API design: everyone else has API keys, they must have a reason, so I better have that too.