well you could say the same thing about 'this is your brain on drugs' when crack was going around. that was also a PSA that entered into the public consciousness and then turned into a joke.

Never been to the States, but from half a world away and just by reading on reddit about it it all looked more like people were making fun of said meth-addicts, they (the redditors making the jokes) didn't seem to care that much about those meth addicts. This was all happening about 3-4 years ago, I'd say, and it's in very sharp contrast with the present-day opiate-related discussions which can get pretty personal. It's also interesting that the HN crowd has also joined the opiates conversation, I don't remember reading anything about the meth epidemic in the past on HN.