FDR, FLCH is a major threat........ When used during approach or hand flying. Look it up. In other phases of flight it is a very useful mode. Just because something is identified as a threat doesn't mean we are all incompetent muppets. No G/S is a threat. It doesn't mean that we should crash, just that the threat needs to be managed. High terrain is a threat. Crosswinds are a threat. Lack of currency is a threat. Etc etc. All everyday occurrences that are managed in various ways.