Because there's nothing hidden about the health disadvantages of a burger, and eating them is fully ingrained into society/culture. WLAN is both new and mysterious (mysterious as in you can't see radio waves), so it's ripe for reactionalism and conspiracy theories, etc. Not that I think WLAN necessarily doesn't have health/wellness implications for people and animals. It may very well be dangerous. But I agree that it's stupid to worry about WLAN while biting into a burger..