That's because you're only using chief
so lets say , um , we just want a wall dimension to be locked , this is very simple , because in a very complex REAL WORLD map , we don't have square walls we have off angle walls we have stuff that controlling them is a little bit hard , and suddenly when an important wall dimension changes anything become destructed it could be better if it was able to do that , like other software , like solidWorks constraint dimension system