It's a silly metric. There could be only one master bot that pings every known endpoint multiple times a second, and that would probably surpass all human activity, too. It doesn't really tell us much about intention or the ability to masquerade as humans.

Where I would start to worry is if there's evidence that bot access patterns are starting to become harder to distinguish from human access patterns, which would suggest that they are, in fact, mimicking or masquerading as humans. I don't care how many search bots are indexing web content, but I do worry about how many social bots are attempting to manipulate or mislead people.