You guys are missing the point.

Of course it's not a problem when there's only one or two healers on a team at any given point in time.

Now try that again with four healers. Or better yet, a team full of nothing but healers. What can you do against that? It doesn't matter if you focus fire because the entire team of healers can EASILY out-heal an entire team of DPS classes. Attempting to pressure all of them at once is fruitless because any single healer can out-heal the damage output of any single DPS.

If the solution is to cap the number of healers available to each side, that would be fine. As it is, with uncapped class compositions available for everyone to abuse, it's only a matter of time before you start seeing more healer-heavy compositions making life hell for everyone involved.