It's important for a lot of people and that's why it's marketed like that. It's also one of the most unique aspects of the language, and the primary goal of the entire project.

According to steveklabnik, about 50% of Firefox's critical security bugs were due to memory safety issues (source: <https://www.youtube.com/watch?v=_-fweBvtifA&t=27m20s>)

Presumably you don't think mozilla exclusively hires shitty developers.