I cannot fathom how it could be "more engaging" without being "harder". There's no way to make it "more engaging" that WOULDN'T make it harder. While we can quibble about HOW MUCH harder, adding a second DoT to manage makes it harder (to contribute optimal DPS). Adding a second casting combo attack of some kind makes it harder. Making heals weaker so that GCD heals must be used more often makes it harder. There is no way to "make it more engaging" that doesn't make it "harder" at the same time. So let's start by setting that issue to bed. Any meaningful discussion must start with us agreeing on basic facts. And making a "more engaging" DPS kit, by definition, makes a harder DPS kit. WAR's kit is "more engaging" than WHM's, and is HARDER. You can argue it's negligibly harder, but it's definitely more involved to contribute optimal DPS.
That said, this is why my personal ideal is to make one healer from each type (pure and barrier) harder while leaving the other alone. This way, healers that want a "more engaging" healer can play those ones. They will still do the same overall rdps, so you get no benefit at all other than "not being bored". You would pick them entirely because you want to be pushed harder, and the ones left alone would be for people that enjoy healing now. Everyone could clear the content and people that don't want a "more engaging" rotation could continue playing as they do now and doing just as much damage as those of you that want to be more "engaged". For example, suppose we leave WHM and SGE as they are now and give AST a 1-2-3 rotation and SCH 3-5 DoTs and Fester/Bane. You will do no more damage - let me make sure I'm making that absolutely clear - and they will be more involved in order for you to even manage to pull the same damage as a WHM spamming Glare. But that IS what you want, right?
And it would also help your case if you didn't conflate two things: Are you upset about healers being "boring" or Hrothgar hair styles? Pick a lane.
That said: It's always a good idea for players to try out different things. I have no idea Yoshi P's character name, so I don't know if he's leveled other Jobs or not, but given the type of person and gamer he seems to be, it's very likely he does play healer sometimes as well and isn't just 100% BLM all the time. But we'd have to verify that somehow.
EDIT:
My god, you can't believe this, can you?
Many people love healing as it is right now. They're part of EVERYONE, and they would most definitely not win. I hate healers in PvP other than WHM, and barely that, because I have no heals I can actually use. The CD on Cure is painful for a person that main heals. There are no healers in PvP and I hate it. The only Job I can even somewhat stand to play is WHM because it has some more healing than the others, but barely, and it requires you blitzing into melee (and often certain death in Frontlines) just to use Cure 3. Your functional Medica 2 comes from using LB. It's totally stupid. It's a garbage system. The PvP rework overall is okay, but what they did to healers was brutal. There's barely any HEALING in PvP now, and that sucks arse.
They did great on tanking and damage dealers in PvP - because the Devs clearly love Tanks and DPS but hate Healers - but they did Healers super dirty in PvP. Every single healer has to be a melee warrior and none of them have distance openers, and SCH doesn't even have a gap CLOSER to get into melee in the first place. I can't see why anyone thinks healing in PvP now is enjoyable. It's passable on WHM but total garbage otherwise. If that came to PvE, I'd either quit healing or quit the game outright.
You people that want and love that aren't healers. You're damage dealers in healers' clothing.
I not only TRY healer, I main healer. I play all healers other than AST (because I genuinely just dislike the Card mechanic and it's too busy/"engaging" overall), and love how WHM and SGE work right now. SCH is honestly too much. I think it needs about 3 less buttons overall, drop Energy Drain so its healing isn't fighting damage, and delete Dissipation, the single most terrible/bad ability in the entire history of the game.
You want to play DPS. That's the problem. Many people do not. We want to play Healers, and don't want you turning our Healers into DPS. You have 11 DPS Jobs in this game to play. 15 if you add Tanks. And two of the Healers, SCH and AST, are already very busy and involved. You have PLENTY of options without ruining Healers for the rest of us.
If you were talking about 1 or 2 of the Healers, as I said above, and doing identical DPS just putting in all that extra effort you WANT to put in, that'd be fine. But that's not what you want. You want to ruin Healers for people that love them right now. And that's unacceptable.
It's funny you mentioned this, did a ZodEx with no Job stones. It actually is possible (though somewhat close), and it was interesting having to lean so heavily on GCD heals again instead of having oGCDs coming out the wazoo that do all the healing for you.