As the title says, I don't really understand. As far as I am aware, there is 3 different types of pet battles, and only one of those really needs to be phased.
#1: Wild Pet Battle - No one else can battle a pet after you have engaged it, you get a buff that protects you while battling. So why does this need to be phased so that no one can see you?
#2: PvP Pet Battle - Battles against other players, just like duels. No one can duel someone while you are dueling them, why does it need to be phased so no one can watch?
#3: NPC Trainer Pet Battle - These are the quest NPCs that everyone has to fight. As you may or may not know, an unlimited number of people can battle these trainers at once. This seems like a pretty good reason to keep this one phased.
So what are the reasons for the first two being phased? Do you think they should stay phased or would you like them to become unphased for spectating and community participation?
I've been experiencing the exact opposite of what you guys are saying happens, I cannot see people dueling pet battles or wild pets. A 10 yard or so bubble around them phases them out. I see the wild pet standing still doing nothing and it says its already in combat with someone, and the players just straight vanish.