If you were a good student of the Constitution, you would have already have answered your own questions.

 

The most important things came first.  Improvements were allowed, but provisions put in place so that it didn't become a Christmas list.  That when changes are made, they are well thought out and not frivolous.  Like a ship, it could weather small changes in direction without someone grabbing the wheel and putting the nation head on into a tree or ditch.

---