My interest is kind of academic at this point, but there was a time - before I got that Nuova Simonelli grinder - I was trying to make it work with a hand grinder. And sort of wondering why it can't be done.
With a relatively coarse grind like that, the spread of particle sizes might have something to do with velocity. At hand crank speed, pieces of bean are sifting and sliding around in the mill and getting scraped and mashed, where at much higher powered speed everything I imagine there's a type of cleaving that doesn't occur at slow speeds.
At the espresso grind I was going for, there's also a problem of adjustment - the burrs might not fit together that close, but anyway even if they do, the two burrs aren't really fixed together on the same shaft, and accordingly there seems to be some play. Some designs are worse than others.
Those are a couple of theories, which sure could turn out to have nothing to do with whether a hand grinder delivers good results or not.