its not managable. Add humans to the amount of sites and data on the web today, and you just can't police it. This is why Google is in love with the algo. OK, there manual reviews, but they only go after very high volume keywords or massive spam reports, when they get it to it.
Saying that SERPS can be policed, with todays and potential tomorrow is short sighted. But like you said, perhaps he is just having fun, a break from spaming his list!
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