It's not that this is nefarious, it's just how it fucked up that makes it such a pain. The root of the problem is a dll which is loaded at windows boot is causing a memory error that crashes the entire system. It's not hard to fix, just remove the dll and windows will boot like normal. Nothing is destroyed, it's just in a bootlock. Unfortunately, the way windows works, is that you have to use windows to remove the dll or stop it from loading, which you normally can't do because the dll is preventing windows from loading in the first place. The correct solution is to use a special mode called Safe Mode, which prevents any non-critical components (basically any dll) from being loaded at windows boot, specifically so you can fix this stuff. Problem is that getting to safe mode and knowing which dll to delete is above the capability of most people, and on sufficiently important systems, access to safe mode would be restricted to administrators anyways. It's a super easy fix, but it's a pain in the ass to do specifically because of how windows works, so people are going to have to lug their asses physically in front of these computers to make the change. And that takes time.
Once it's fixed, it's like nothing ever happened. Nothing is permanently broken. It's just a stupid update that pushed a small piece of code that has memory errors, normally a routine thing but in this specific circumstance a huge problem. It's not nefarious, it's just shitty administrating by lots of these companies. Ideally, you wouldn't just push updates to your critical systems the moment they roll out. You'd sandbox them, test them in a controlled environment, then deploy the update to your system, for this very reason.
This isn't really a huge, evil attack. It's more like shitty IT and code deployment in the worst spot. Don't attribute malice where incompetence will do.