Also, the update process for these systems in question would be just as much to blame. Don't want updates twice a month... don't apply them!
Ie, You don't check what the latest version of the kernel is, you trust your distribution to package a version and apply relevant patches.
This is the main purpose of a Linux distribution, to take away the stress of tracking every project it uses.
Quick, what's your version and the release cadence of: top, bash, coreutils, systemd? It's very likely you don't know, don't care and just get them with the distribution. Nobody's forcing users to care about this either.
Since when did we expect OSS to have QA process that is not the users ? It's telling that the co-opting of OSS by business led to this expectation that OSS is something to consume rather than participate in.