Firefox is just as bad
I do like very much that Firefox is almost completely open source, and that ssllabs.com has a high opinion of it.
That being said, critical Firefox vulnerabilities are issued for my Linux distro at LEAST once a quarter, and more commonly once a month.
https://linux.oracle.com/pls/apex/f?p=105:21:0::NO:RP:P21_ADVISORY_TYPE,P21_RELEASE:SECURITY,7
If a piece of software has had 5+ critical vulnerabilities in a calendar year, then it's time to halt development for a security architecture review. There should be sound reasons why a user community should endure a stampede of exploitable flaws - reasons that pass the muster of an independent review.
(This does seem to include the Linux kernel itself.)