[sgpratley]

I'm very surprised they are releasing this data

I'm not, what I'm surprised at is that the button saying "sign up with these keywords" isn't in huge neon lettering.

Now the top end of the generic phrases are so expensive it's much harder to make a profit, they need advertisers to start spreading their campaigns more widely.
Tools like this give them the confidence and justification to do that (even if the data is pretty shonky!)