If all kernel bugs are security bugs, how do you keep your Linux safe?

Stuff like SELinux is an incredible tool that can help protect against most threats, and really there is no reason for not utilizing it in present day.

Not much of an article. Do yourself a favor and read the LWN one:

https://lwn.net/Articles/961978/

tl;dr: The Linux kernel team view all bugs as a possible security issue. The CVE assignment teams tries to minimize the number of Kernel CVEs because corproate policies mandate fixing CVEs in 30/90 days. There's a lot of politics.