True, I think that concept can also go ways to explain why when we aren't talking terrorism, but even just behaviour online, so much of the anger/resentment and what we refer to as 'trolling' these days is males. Generalising a bit, but I bet if we were to know who a lot of the anonymous avatars saying terrible shit online to other people were, it would largely be males feeling "stuck in a rut". There can be truths that many young males, largely talking teenagers, can go through stages of issues with aggression and hormones. However, putting that aside when we start to see people in their 20's/30's and later behaving terribly on the internet (not just 14-year-old Halo smack talk), you can bet it is still males, and many of whom have poor life/job prospects. Poor sexual/partner prospects also kick up behavioural issues. This is true even with terrorists. Many will fit the category of not just males, but single males.
[snip]
Going a bit OT, but I think there is so much value in breaking down some of these discussions to micro-levels like this rather than just focussing on terrorist groups/cells. There has to be research and understanding around the individuals themselves who carry out the atrocities and why they get radicalised. Especially why it is nearly always males.