Disclaimer: I'm an infosec student/enthusiast, so I may have a different perspective. Also, it's late; it's entirely possible that this is sleep deprivation talking.
I think it's more a case of the subject being so important that it's not really something that you can take shortcuts with. When it's something so critical to daily life as the internet is becoming, it's imperative that all code made for security purposes is carefully considered, and architected to avoid the tiniest bugs. Hobbyists or amateurs (myself included) are not necessarily qualified to judge what might constitute a critical bug, and that is one of the reasons the barrier to entry in the field is so much higher.