No of course not but that doesn't mean that it's common for instances with a zero dps healer to take two or three times longer. Such a statement is a blatant lie. Most healers do dps but most healers are not top tier savage players with BiS gear. Most healers are incapable of pulling enough dps that if they stopped the instance would take several times longer, either due to their own skill, their gear, or the pugs they're landed with demand frequent healing.
For someone to truthfully say "when I do an instance with a low or zero dps healer, it takes two or three times as long" they would have to be playing with exceptional players all the time...or their own dps is so bad that they need even just a generic pug healer's dps to carry them.
I completely agree with all of this. I just don't agree with the idea that a zero dps healer outside of savage is automatically assumed bad regardless of their healing ability. Especially when tanks and dps are rarely scrutinised in the same manner for their lack of involvement with their secondary roles. And especially when some of these tanks and dps are the ones criticising healers for not doing enough dps. The hypocrisy drives me mad.
I don't approve of zero dps healers. I rarely speak up when I encounter them outside of savage because a lot of people don't take kindly to criticism no matter how small, and I frankly don't want to invite drama if I don't have to. I recall saying something about it once, and it was because I died every time I got caught in The Sable Price in The Aery. However a lot of the blame is also on the other dps because their damage was low and they were slow to react.
Context matters when judging people. If I see a zero dps healer who is healing a lot because the group demands it, and I know if I was healing I still could insert dps, I don't get annoyed. Why? Because they're clearly pumping effective numbers somewhere. If I see a zero dps healer just standing around doing nothing for ages because the group doesn't need healing, then I get annoyed. Why? Because they're doing literally nothing. I get more annoyed when someone does nothing than when someone is playing sub-optimally yet are clearly putting in effort. There's also the context as to what content you're in. I get far less annoyed about a zero dps healer in Brayflox normal than in Ala Mhigo. And if the player has a sprout or returner tag, I'll be more forgiving than usual.
But in ex and savage I have no interest in playing with a healer who doesn't do dps during healing downtime. That content is where I reserve my harshest judgement because it demands much more than just fulfilling your primary role. In casual content I'm not overly concerned about what others do as long as things die in a timely manner without incident.