Echoing most of the above...
1) We do not have better minds nor hearts than the Framers, so why assume superior results from a new Constitution?
2) COTUS is at root a set of principles. The failure is not in the principles, but in not living by them.
3) The only reason to revisit the COTUS is to acknowledge that we now adhere to different, I would argue inferior, principles. The solution is a return to the originals. Our present path certainly isn't moving in that direction.