Redemption and forgiveness are also Christian and Jewish philosophies. From everything I have read these are not Islamic concepts. You can’t simply ask Allah for forgiveness, you must actually so something.
I have read some analysis that suggests that the 9-11 hijackers, all from medical class families and all had spent a significant amount in western society. After having engaged in all manner of western decadence (and enjoying it) they were easily recruited by radicals. They lay a major guilt trip on them and, I guess as this article suggests they are overwhelmed with shame.
The radical then offers them a chance for redemption, the only one available under their understanding Islam. I think it’s a valid physiological analysis.
My bad