The irony is that anyone using IDEs is using the same idea, as all of them use a virtual filesystem layer to simulate the same capabilities as the image approach.

Not really, because you still recompile and start the program from scratch, rather than modifying the code that executes on the still-existing data structures.

Edit: rather than just naysaying, it occurred to me to reference the notion of Orthogonal Persistence, which the image-based approach provides (not without drawbacks) but IDEs typically don’t. Previous HN discussion: https://news.ycombinator.com/item?id=39615228