This is just my opinion but I think it's great for consumers and a good restriction for developers.

As a consumer you shouldn't be running unsigned software because you're putting not only your data at risk but any data you have access to.

And as a developer on mac you can still run anything reasonably well in a VM. If you're using node, you should be running that in a virtualized environment in the first place, albeit I'm too lazy myself to always set that all up.

Actually it's pretty amazing that now we'll be able to run an entire x86 OS environment on an ARM chip and get very usable performance too.