Total red herring.
Case in point #1: I currently own (personally) five Win7 and one Win10 installation; two Win7s are on metal (a laptop and a desktop), and the others are VMs. All are patched up to date, and none have ever stopped working.
Case in point #2: At my job, I tend to about 75 Windows 7 and 10 machines, mostly on-the-metal desktops and laptops, the rest VMs. All are patched up to date, and none have ever stopped working. None, ever.
The above machines run the gamut in hardware, brand, peripherals, options, etc. If the problem you fear was even somewhat common, I'd have experienced it.
Windows 7 updates nearly always require a reboot. When it doesn't come up after a reboot, the problem is almost always a kernel-level driver conflict. In most cases, it clears itself after one BSOD/reboot. In a few cases, it's necessary to restart in "Safe Mode", an option shown on the next boot screen. The majority of those who have experienced a BSOD had installed third-party device drivers which had a conflict with an update that also affected that hardware. That's what Safe Mode startup is for.
The vast majority of Windows 7 users never experience an update-related issue of "the computer stopped working" -- as in "Windows doesn't come up at all". Moreover, a lot of those turn out to be memory or other hardware issues unrelated to the update, but the reboot required by the update brought the hardware issue into play.
The actual percentage of Windows 7 users whose machines stop working completely due to an update is extremely small. And those few unfortunates generally find a way (another computer or a friend's computer) to contact Microsoft support, which is generally quite good at getting it going again. Microsoft "owns" those problems, and it's on them to fix them.
I suspect your sense of perspective is somewhat skewed by your dislike of Windows, or of Microsoft, or something similar.
Question #1: Do you seriously propose recommending that ALL ~1 billion Win7 users NOT install the security updates, because an extremely small percentage of users experience serious trouble?
Question #2: What operating system do you run, that is immune to "non-start issues"?
It’s not even slightly a red herring. It’s a real-world situation, the kind that is common with so many people running so many different types of software and knowing so little about how to operate their computers.
Now what if the machine in question was business-critical for somebody?
Can’t count how many times I went into a situation to do one simple and routine thing, and then had to fix an entire environment because that one thing sent an unstable situation over the edge. The situation described above is not hypothetical or theoretical, it is an actual situation I have encountered multiple times doing IT support over the years.
As a result of this variability of environment, generally correct advice can be bad in any particular case.
My comments are completely platform-neutral and apply to all systems and platforms. One simply cannot make a responsible recommendation for any particular case without knowing the whole of the situation.