I put that restriction on myself, a selection of reasons follows: I don't use AV software but my employer requires it on machines in its domain, I won't allow remote management of my personal hardware but my employer uses remote management for wiping lost devices, and it helps to maintain a clear separation between personal and work time. All of the requirements my employer places on its hardware are reasonable for work hardware and I'm not opposed to these measures, but that's why IMO work hardware needs to remain work hardware - you can't compartmentalize a single device so that say an accidental remote wipe only affects your work files on the machine / phone.
If you put your restriction on yourself then you are responsible on fixing the situation yourself. Its not acceptable to simply say 'I would not work at all'.
The "situation" here refers to having to work from home without notice due to Coronavirus. That's not a situation one thrusts upon themselves. I disagree that that's something one should be responsible for preparing for by always carrying their work laptop home. In fact, doing that puts the laptop at a risk of theft when in transit, which before the Coronavirus outbreak was definitely seen as more likely than a random epidemic.
This is no different from the office building burning down or having to close for a few weeks for a similar reason resulting in working from home without notice. In that scenario, I'm also not responsible for "fixing" the fact that some of my equipment stayed in the office and is now not accessible to me, preventing me from being able to work.
It's a really, really good practice, whether or not one's firm mandates it. An employer has every right — moral everywhere, legal many places — to monitor your usage of its hardware, software and networks, which implies that if you are doing personal things (say, your finances, or even social networking) that it would be exposed to your passwords and activity.
Meanwhile, you have a duty to be responsible with your employer's data. Your employer can secure its own hardware, but it cannot secure resources you own — which means that if you use your own hardware & software to work with your employer's data that any breach is your fault.
Given those realities, I prefer to use my employer-issued hardware, software & network for my employer's work, and my hardware, software & network for my own purposes. That way my employer is secured from my mistakes, and I am secured from my employer's mistakes (or nefariousness).