Healer should not dps in the dungeons?

[Chiramu]

I was the bard and Healers mustn't do dps.

;...;

Seriously, some guys are "special". I joined to DF, Tank-scholar-Ninja-Bard (me)

They asking me why i played foe in boss or trash mob encounters. Hello? Ninja has spell damage abilities and the scholar can do dps.
You can be casual, but not a lazy player. You are paying for play, click one button or press r1 + a, it's fun for you?

What is this suppose to say exactly?