Many distributions have a dedicated security team that has to sign off any patches to security-critical software. Debian's position is that they do not have the resources for such a team, which is fair enough, but IMO the conclusion should be that they don't have the resources to be applying their own patches to security-critical software.

More subjectively I get the sense that Debian packagers patch more aggressively and generally think the Debian way of things is better. This isn't completely groundless: there's a lot of very high quality engineering in Debian, and for a long time their package management was head and shoulders above others, especially if we're talking about C programs/libraries where upstream dependency management is very weak. But it's also made for a culture where packagers think they know better than upstream maintainers, and an approach that ends up conflicting quite a bit with newer languages where there is high-quality dependency management in the upstream builds.