Probably because I've not read that thread, I don't ready every single thread.
But 80% of WHM's you get don't heal and just leech? I've acknowledged, yes a portion of players are like that. So I figure you're either overstating the issue, you're misreading your co-healers in many cases or somehow your experience is big anomaly.
Apologies if I am a bit of a stickler on it, but I guess, one of my frustrations is that I see people overstate or poorly represent issues and SE act on them and we can see how SE has already gutted healers on this whole "healers shouldn't DPS" row and people complaining about healers DPSing and now we have a really dumbed down DPS rotation that's and healing itself is too easy most of the time that we are DPSing most of the time. They've got rid of different flavours to playing after people complained about healers screwing up, like Cleric Stance, which they just got rid of because people mismanaged it and people complained about healer DPS, whereas, they could have improved on it.
But it's just not just specific to this but people seem to have a habit of overstating the extent the things that annoy them are a problem and the impression it gives is that it is a bigger & more widespread problem than it actually is.