Most of the time I try to be nice and help explain mechanics and stuff to people, but sometimes you can't cure stupid/bad. Yesterday, as an example, I was tanking LI HM on my Jugg alt (full 61s augmented) and was put into a LI already in progress on the second boss. I get in, make sure everyone knows the mechanics, which pipe console they are going to, etc. I then pull the boss and within a matter of minutes proceed to die. Three pulls later and it is quite apparent our healer is terrible. I talk to him about it to help his rotation (my first main was an op healer), but he still keeps failing. Upon closer inspection, I realize he is in full war hero with some elite war hero gear. I make the comment that this might be easier if he was in PvE gear, but he then responds by telling me I'm stupid and why would he want a few extra stats when he could get the player healing bonus provided by expertise. I almost facepalmed in disbelief of the stupidity. I tried to explain that's not how expertise worked, but he wouldn't hear any of it. Perhaps the worst part of all this is that LI HM can be healed in WH with partial EWH pieces if the healer is actually good. Unfortunately, this guy was both bad and dumb.
1/ War hero can be good enough for EC HM, while I don't personally agree it should be that's another argument. The fact is it's good enough for a lot of tough end game content including LI HM, even better than the columi you described as good enough.
2/ The healer was probably on about the set bonus you get with PvP gear is better than the set bonus PvE gear provides for his class. Now with BM gear (for the shells) gone I could see a lot of ops/scoundrels taking up war hero instead.
And finally, are you sure it was the healers fault or was he just an easy scapegoat to pick considering you all died and he couldn't keep you up? I've played all three roles of this flashpoint now. and by doing so not only I see where other people go wrong but where I did in the past too. My first commando heal run of LI HM was interesting, we had a few wipes and I was worrying that my healing wasn't good enough due to running out of resources trying to keep everyone up especially on sav rak. Then one of the dps quit, a new one joined and all of a sudden any issues I had with healing went away and we nailed the flashpoint without a wipe or death after that.
How was that? Because that DPS who left was getting hit hard and taking too much damage (for whatever reason) and trying just to keep him alive was putting myself out of resources and that chain effect affects the rest of the group. Maybe it goes further than that and is an agro issue due to no guard off the tank but the new dps that joined didn't have any issues so he probably just wasn't being careful.
At the end of the day there could be a number of factors to consider as to why a group fails, if everyone dies quickly it's not always the healers fault.