and yet neither of them are wrong. having more to heal is obviously the better solution because we're talking about healers... but we are on lvl 100 now. you cant change all that content. you can change new content AND give a few more dmg buttons... i think thats reasonable
also, there will always be weaker player. groupmitigation and dps healingskills will help them, but you cant just make it unreasonably hard in casual content. a few more dmg skills will give the better players more things to do.