It's not so outlandish. I've had people in law enforcement tell me that radical Islam is of secondary interest to a lot of these terrorists ... and that the real motivation for their actions is that are complete losers with a death wish who want to make a name for themselves on their way out.
The pathology, according to the folks I've dealt with, is almost identical to what you find in the Columbine killers or Adam Lanza in Sandy Hook, CT.