Developer bad habits?
Possibly developers have been security slapdash for decades because it just gets in the way of doing cool stuff quickly.
Back in the day the operational staff probably kept them nicely caged in their festering pit of cool and cleaned up the more obvious stupidities during testing and deployment.
These days you don't need that expertise because DevOps and Cloud. Code it, click and there you go. New live system. Disrupt, baby!
Quality is boring, though, init.