Some of Amazon's facilities have some seriously awesome robots, and their operating practices (while occasionally...horrifying) are still really effective. I suspect that this agreement is actually aimed more at startup wannabes playing at corporate espionage. Which seems really silly...but considering that fast shipping is their lifeblood, if someone who worked for them in a capacity that could play with their warehouse toys started "inventing" new techniques for running a warehouse or building better robots, that could hurt.
Yeah they can't sue warehouse workers because what the hell are they going to get out of it. But they'd love to find ways to sue the next Kiva if they can't buy them.