The Keyword Planner restrictions Google set into place a couple months ago were not to just block bots but also to prevent "bad actors."
Google's Jerry Dischler, the Vice President of Product Management at AdWords said at SMX East yesterday that the restrictions were for "bad actors."
In fact, he blamed "bad actors" several times when talking about these changes. He did not specifically call out bots or SEOs.
I guess bad actors could be building bots or they could be using the tool for spamming purposes.
He also added that the vast majority of advertisers should have no problem accessing the full data. If not and you are a good apple, then you should reach out to him. I know he is accessible on Twitter at @jdischler.
Here is the video embed, go to the Q&A to listen:
Forum discussion at Twitter.