This Twitter exchange from earlier this year illustrates the sentiment perfectly: https://twitter.com/voodooKobra/status/494466665883910144
This idea (that I have encountered over the years) has always struck me as silly. And yet, I've never succeeded in extracting a straight answer from anyone about why they believe that someone cannot simultaneously have some working knowledge of security and enjoy building PHP applications.
Is there anyone on HN who knows the answer? Is there anyone reading HN who shares this belief?