I agree with both new and Mike here-- I liked having that crutch, but really, it's my own damn fault when it happens.
Another place where the 5/5 PC came in legitimately handy is the situation in a playoff series where you want one guy to start the game after the next if you win the next game, and another guy to start if you lose (very common both in HBD and real life, most common in game 4 of a 5-game series). In the past you could slot one pitcher, then set to 5/5 and switch to the other if you needed to, and if you let the opponent know what you're doing in advance it's not unethical IMO. You just don't have any option for conditional starter choice in a playoff rotation any more.