Tee shots that absolutely require the player to hit either a large fade or a large draw, and admit no other option.
Tee shots that all feed to one area, leaving a turf maintenance problem. (This seems to me to come up with reverse camber fairways more often, but that may be just my impression.)
A fairway bunker that should function as a savior bunker, but is misplaced even slightly and intrudes too much into the fairway to make an already challenging hole too difficult.
Too many forced carries on the same golf course, either off the tee or on approaches, that cause difficulty for players in selecting the correct set of tees from which to play.