Yeah, well, here's the thing about WoW. In a WoW 24-man raid when you needed seven healers then you brought seven healers, and when you only needed three of them then you only brought three and four had to sit out. You didn't have the static 2 tank/4 DPS/2 Healer party format, and sometimes you'd bring one tank and others you'd bring three of them. Even in 10-man content you only brought that 2nd tank if you needed it, and pared down to only as many healers as was required for the encounter. Raiding in most of WoW has often been an exercise in having "alts" and "player rotations" to fit the encounter, and while this eventually became more tolerable with the introduction of "multi-spec", it took many years and a couple of expansions for it to get there.
But let's talk heroic dungeons, where crowd-control was a major design focus. Trash mobs in WoW could not only wipe the party, but often had unique abilities that needed to be countered. To combat this, there were an excessive amount of creative disorient, bind, stun, trap, and polymorph effects to allow you focus on specific mobs, none of which triggered diminishing returns when used on non-players, and when it all worked well as a priest you could still squeeze in a few smites if you wanted but they did piddly damage if you were running a healer spec so no one blamed you if you didn't. That's not the case here in FFXIV though. Not only are healers equipped with potent DPS spells that aren't critically restricted by "specialization trees", but the only CC to speak of is sleep and repose, with bind and heavy occupying a gimmick tier due to dimiinishing returns. It's not the same game as WoW, and all the disadvantages inherent in healer DPS in Warcraft aren't present in the systems of FFXIV. Stone and Aero HURT in ways that shadow priests would consider acceptable, and Holy is a wonderful thing, and given encounter focus does not require constant heal attention to deny the very toolkit of the class is wasteful.
You are free to ignore your DPS toolkit, and in situations where you aren't sure the party can handle a few moments without your supervision then I strongly recommend you brace to heal, but if you are able to leverage your class ability set completely then that's just a sign of a player who knows how to get the most out of the tools he has to work with.