I always found it too fragile. There’s a reason why smalltalk VMs have such good recovery features, it’s incredibly easy to brick your system when it’s all a network of objects, and I’m sure anyone who has worked in smalltalk has done so many times
Just restore unsaved changes when you launch the same image again. That's robust not fragile.
You may as well claim that computers are robust because you can just buy a new one. It has nothing to do with computers
Pretty sure ST-80 doesn’t even mandate recovery features, which is pretty scary
(I’m not sure that’s exactly what happened, probably the system crashed before garbage collection could happen. But it was definitely a guaranteed insta-crash).