As the title says, i believe that it would be better for both players and Blizzard if PCT was free. Here's my reasoning:
Ok first thing lets see how many people have payed for a PCT. This is hard to estimate but i'll make a rough guess and say 1 out of 5 people. Now lets see how many people have quit the game due to their server being dead, or massively imbalanced, or because of any other problem which could have been solved with a character transfer, but instead chose (or were forced; many players are 13-18 years old so they dont have their own credit card) quitting instead of paying. This is even harder to estimate, i'd say 1 out of 20 people so lets say i'm completely off and its 1 out of 40 people.
That means that the ratio of people who payed for a PCT / people who quit because PCT wasnt free is roughly 1/8. Taking in account the fact that a PCT is worth roughly 2 months of subscription, if PCT was free then the "quitters" would have to play 16 more months for Blizzard to have the same profit, which they most likely would have done.
In conclusion, i think Blizzard should just change the PCT system. Either give each account 1-2 free transfers (but pay for subsequent), or completely remove its cost but give it a 1 year cooldown to prevent "good" servers from being massively flooded, or only allow free transfers to players with good reasons (dead server).