People updating it.
Way more problems I've seen here and in personal experience in updating NVR and/or camera FW simply because there is a new version available than with actual security breaches or system failures because of outdated FW.
have there been specific incidents with specific FW versions that were a true problem and an update was vital? Sure, but few and far between. Very few
The old adage "if it aint broke dont fix it" is never more true than with technology.