We can't do that, because then the player would have to pick out the Spitter from the crowd by actually looking for it, or waiting for it to attack.
This requires a certain degree of intelligence that's just too advanced for the modern gamer.
It's much better to offend the smart, capable players, seeing as how they're obviously in the minority, and not put off the hordes of idiots who will complain if the game presents them with even the slightest challenge or demand on their attention.