Help API requests probably should not count towards the no-key API limit. The most likely usage scenario of the API without a key is when people are trying to learn it, which means reading the help a lot.
It also doesn't help either that the
<method>?help form redirects and generates two requests towards the limit count.
Update: People have discovered that if the first request does not have a key, that sets the daily limit. It's unlikely devs will remember to add their key when making a request to an API in the browser to read the help (ie
/stats?help), thus triggering the 300 daily cap.