The arrogance of some people

[Ghishlain]

1. They DO consider Healer DPS: just the minimum DPS that they do when they're healing: Think Assize, or the DPS increase that comes with Fey Wind, etc.

FYI, later in the interview, Yoshi-P says this (I've included your quote as well just for context):

Let's get right into it - we've seen many posts from readers relating to end-game content. When you go through development, how do you decide how to set the difficulty? For example, the amount of DPS required for each particular content.

Yoshida: When we make battle content, first we determine a minimum assumed item level required to clear. Then, we determine the total amount of party damage required to clear, taking a minimal amount of damage from tanks and healers into account during this calculation.

What do you mean by minimal?

Yoshida: Basically it's the damage from tank auto-attacks and the basic skill rotation used in order to maintain hate. We add this to the party damage needed. However, we often use zero in the calculation for damage required from healers. In other words, we only take into account the amount of damage necessary to perform as a tank or a healer and we don't take them into account as actively participating in attacking. For the clear assumption on DPS, we calculate the 100% value for the item level and we reduce that by 10 to 15 percent for the amount required to clear.

I don't really want to put my foot into this debate because I've done it to death on the healer forum, and I don't intend to sift through 1K+ posts of what I'm pretty certain is the same thing as discussed there. But just wanted to present the entire quote so everyone can understand the context it was written in.

Source of mine and KaitlanKela's quotes - Slycer translation on BG of 4gamer interview.