It just takes one motivated enough to write a parser for javascript for common munging techniques.

See, that's the thing... I'm not a spammer (really), but if I were, I wouldn't think the average person taking advantage of munging techniques would be remotely worth the effort.

Spam preys on the 1/10,000th of the population that gets excited about lost millions, internet lotteries, cheap pharmaceuticals, or security warnings that appear to be from their banks. People who take the time to obscure their primary e-mail addresses tend to be keen enough to not fall for these things...