Welcome to WebmasterWorld Guest from 188.8.131.52
If your ads look or smell like you have product to sell, or your landing pages do, you'll pay more.
I'd say that if you're trying to trick people by using less than relevant keywords, ads or landing page content... or if you're thinking that everything is just a volume game (and someone searching for tie dyed t-shirt should land on your button down tuxedo page), then you'll pay dearly... or be blocked from the auction completely with absurdly high min bids.
forced relevance and specificity, that's all. G does it so people maintain an interest in cliking on ads in general, that's all.
conspiracy theories are fun, but... that's all.