@Logicfest -- I do believe one of the reasons those aren't used in homes more often is because it is expensive to put up wooden roof trusses that are both functional and look good.
Say you have a pile of boards you want to use for roof trusses. What you have is a bunch of unfinished wood that you will hold together with very utilitarian looking, metal mesh strips that nail to the boards.
In a word, yuck.
You want to make all of that look better? You will spend money and man hours staining or painting the boards and even more money on connectors that are more attractive.
For most homes, the extra cash isn't worth it. You will add unnecessary expense to the home, so why bother?