The main issue seems to be the amount of damage that the healers can take, making them better at tanking than tanks, since they can also heal themselves. The best way to win a PvP Arena fight is to have a composition of a healer and classes to defend the healer. But, how do you win against this composition? Well, you do your best to CC the ones defending the healer and then try to burst him as quickly as possible!
If you go to the thread where the players are arguing about healers, you can see that the complaining players aren’t putting too many arguments in their statements, which means that they’re also getting a lot of dislikes on said comments.
Read the whole thread and you’ll probably be confused, as many players whine about the invincibility of the healers in PvP, while others are surprised that they are having any trouble dealing with them. It’s probably the players’ lack of skill/understanding of the match-up that they’re going against, so the best way to counter these healers is to read up on strategies on and how to counter them effectively, or better yet, play said healers and learn what their weaknesses are!