People don't patch systems and that's all there is to it
Recently (ie, today) there has been all sorts of commotion in the news about various organizations getting badly hit by malware that exploits a vulnerability that was patched by Microsoft in MS17-010, a patch that was released March 14th. I'm sure that the usual suspects are out in force pointing their fingers at organizations for not patching. In response to this you might want to read, say, Steve Bellovin on the practical difficulties of patching. I agree with all of this, of course, but I have an additional perspective.
Although one may dress it up in various ways, real computer security ultimately requires understanding what people actually do and don't do. By now we have a huge amount of experience in this area about what happens when updates are released, and so we know absolutely for sure that people often don't apply updates, and the extended version of this, which is people often still stick with things that aren't getting security updates. You can research why this happens and argue about how sensible they are in doing so and what the balance of risks is, but the ground truth is that this is what happens. Much as yelling at people has not magically managed to stop them from falling for phish and malware links in email (for all sorts of good reasons), yelling at people has not persuaded them to universally apply patches (and to update no longer supported systems) and it is not somehow magically going to do so in the future. If your strategy to deal with this is 'yell harder' (or 'threaten people more'), then it is a more or less guaranteed failure on day one.
(If we're lucky, people apply patches and updates sometime, just not right away.)
Since I don't know what the answers are, I will leave corollaries to this blunt fact as an exercise for the reader.
(I'm not throwing stones here, either. I have systems of my own that are out of date or even obsolete (my Linux laptop is 32-bit, and 32-bit Linux Chrome hasn't gotten updates for some years now). Some of the time I don't have any particularly good reason why I haven't updated; it's just that it's too much of a pain and disruption because it requires a reboot.)
PS: I'm pretty sure that forcing updates down people's throats is not the answer, at least not with the disruptive updates that are increasingly the rule. See, for example, people's anger at Microsoft forcing Windows reboots on them due to updates.