first, the arithmetic of the amendment confirmation process requires such an arduous supermajority among the legislative bodies of the states, that runaway amendments are virtually impossible. It would require only 13 legislatures of 99 to defeat an amendment.
second, the daunting arithmetic also means that no amendment of any sort has a prospect of passage unless there is a life changing national emergency, such as a fiscal death spiral. Otherwise the author is correct, the ordinary course of American politics will sadly not save us.