Hesalite was preferred to crystal in space ships as it doesn't shatter into tiny pieces if it breaks. Tiny pieces of crystal would be nearly impossible to gather up in zero gravity and could cause a problem for equipment/astronauts if it's floating around.
On earth, where the majority of wannabe astronaut moon watch wearers will forever be based it's more useful to have a watch glass that doesn't scratch if you sneeze on it.
Don't you dare tell me I'll never make it into space.
Depends if you have a scratchy scratchy watch or a muggles crystal, really.
Everyone knows you have to have the watch before they will consider you for Space School.
Don't you dare tell me I'll never make it into space.