To clarify on this a little:
This line of thought is kind of out of date now and has been for a while. SE's raid design approach shifted quite a lot with Sudo moving be it for better or worse. There are examples of duties where the healer is forced to DPS either for a personal damage check (eg: O5N Phantom Train) or simply that the entire fight is clearly and provably tuned with healer DPS being taken into account (eg: E8S Shiva).
I'd say it's a fair point that healers were initially designed around healing first in ARR because not enough attention was paid to our damage potential, this lead to frequent occurrences of healers actually out DPSing proper DPS jobs in dungeons with regularity through ARR and HW. Now SE clearly pay much more attention towards keeping our damage in check even if the kits themselves have gotten more simplistic.
Too neat an idea to get buried on an old page within 10 minutes. I like++