There's a reason a player plays either all gut, all poly, or a hybrid. There are advantages and disadvantages to each. Just like there's a reason some players who hybrid their strings likes one or the other in the mains. It all comes down to power, control / spin, and feel. Depending on what is most important to the player he will like one or the other in the mains.
Everyone has the right to be stupid... it's just that some people abuse the privilege