You know, I've got to disagree with the base assumptions here. Coming from a game like heroes of the storm, where healer is it's own specific role, having primary healers to play against is not itself a boring role to play or frustrating to play against. Some people really enjoy characters like that, and as long as the healer isn't also dishing out incredible damage or reaching tank levels of survivability, it's really not a problem to play against. They become a dive target, someone you prioritize to win a team fight, and they can change the dynamic of a team fight as well, turning it into a longer term conflict of thirty seconds to a minute of straight combat rather than fifteen seconds tops and done.
I'm not saying dedicated healer builds are definitely the way to go, but ponpon's basis for being conceptually opposed to the idea is definitely flawed