Do those 'people' even exist? In a game where you have umpteen different options for pure damage-dealing, I'll hazard a guess any existing players hoping to convert Healers into pure-damage dealers are near non-existent. If it's some sort of sarky dig at those on the 'do some damage' side of the spectrum, bear in mind that asking for an idle player to contribute isn't the same as asking a class/role to convert into another class/role entirely. I guarantee 95% of those who have a problem with AFK'ers would actually be relatively (if not almost entirely) happy even with sporadic damage - an Aero here, a stone there. Every little helps. If I see someone doing something, however frequently or infrequently - it is infinitely better than doing nothing.But I digress, here I am describing how SE could make changes that would likely result in rage-quits by people who want the healer to be an extra DPS
I'm one of the most aggressive in terms of dealing damage as a WHM whenever possible (without any neglect to my primary goal of keeping people alive) - yet that doesn't mean I'd advocate for Healers to become comparable to regular DPS, or actually BECOME a DPS. I simply know, when being healed rather than healing, when said person has freedom to act, yet decides to spend that time gawking. As for the topic in general, FFXIV Healing appealed to me more than usual, simply because I was given Healing & Damage spells and told to go nuts. No caveats, no funky mechanics, no restrictions - just 'here's a tool-set - make the most of it'. Compared to some of the other games (old and new), here's three extreme examples from top, middle and bottom of the Healing/DPS train...
Old-school WoW - with no cross-class or multi-talent function. Levelling a Healer involved signing an invisible contract: you will hit like a wet-noodle and be utterly irrelevant unless there were non-self healthbars floating around in need of extra health. Even if the wet-noodle-damage didn't phase you, you'd learn that it would also be a huge mana-sink despite being akin to battering mobs with a bag of feathers. Actual group content involved light to no damage contribution at all given meagre damage output vs how healing-intensive the game was and how important mana-conservation was, unless you wanted to scream for innervates all day. When someone tries to get involved with this circle-debate on the basis of "Yeah, well, I played WoW - it's different there", that is the point - it's a completely different game, with a whole 50-70 levels worth of time to figure out the differences. I don't entertain people who proclaim the reason they're AFKHealing is because they're 'used to' more healing-intensive play-styles of other games. This is not that game.
Allods Online - probably my first taste of a Healer/DPS mixture that didn't fall into the trap of trying to replicate WoW's success (re. wet-noodle Healers), which is ironic given anyone who hasn't played it properly will call it a literal WoW clone. As a Summoner (pet/DoT centric Healer/DPS capable caster), both healing & damage spells use the same resource (drops of blood), with base blood-generation being awarded through light damage-dealing. 90% of heals and 90% of damage use the resource, so one way or another, you WILL be doing damage whether you like it or not, as the main damage spell is the only non-healing and non-CD based method. It works well given it doesn't force you to be 'optimal' at the damage aspect of things (unless you really want to push yourself) - and isn't as restrictive or as simple as it sounds (just giving the basic concept). These days you can spec as pure damage, healing, or support - but the core is relatively the same.
Riders of Icarus - at about mid-level, the ratio between damage & healing spells on Priest is quite literally 9:1. Between three bars almost full of spells, I can only really remember having access to three healing-capable abilities - the rest are all damage or CC (typically both). Given it's more of an action-MMORPG, it makes sense. Still, I'd like to see pure-healers wading into a game such as that and proclaiming that 'my role is to heal, therefore 90% of my kit magically doesn't exist'.
Here in FFXIV, you are healing/damage capable and charged with judging the best use of the time given to you - that's it, no bells, no whistles. Doing one or the other relies on the MP at your disposal and the freedom allowed to you by your team vs the content in question. If, during any spare time, you choose to stand there gawking while others are actually doing something, then you're the last person I'd want on my team (no matter what role you play as). I might just start tanking again and using overpower/flash once or twice then stand there in idle-animation letting mobs hit me while I bugger off for a smoke - you can bet you won't be happy about it, but so what? If Healers can do it, I want a piece of that lazy pie too.