DPSing as a healer

[KitomiSaitichi]

(a) There are players with varying levels of skill of gameplay, these being factors of knowledge, reflexes, timing and predictive capabilities and foresight

Knowledge lets you anticipate the mechanics and react proactively, whether it be applying a sleep / fluid uara to interrupt a mob, a stoneskin to mitigate AoE damage, or to do X, Y, Z mechanic

Judgement and Foresight lets you react appropriately when an unexpected situation arises, making the right decisions at the right time, such as a secondary mob coming to the current pack of mobs; do you sleep it, provoke and shield lob, stun - or if suddenly someone gets a spike critical - do you swiftcast resurrect or do you get ready to dodge the mechanic thats about to turn you into a rock; are your party members going to come closer to you or do they spread out when they take AoE damage. This changes what skills you use at what time.

Reflexes and Timing allows you to make the accurate fine motor movements necessary to press the right button at the right time, the tank might take 2 "ticks" of mobs hitting before they require a heal, a "spike-flat-spike-flat-flat-spike" pattern or whatever is conceptualized automatically when you become adjusted to healing

(b) The end-game goal is open-ended for all players
Nothing in this game requires you to do specifically one thing or another for enjoyment. Not all players care about the dungeon being 20% faster. Not all players need to know that you can save '1,695 gil in repairs' by leveling crafts. Not all players need to know 'A-B-C-X or Y' rotation does 16% more damage than 'A-B-D-C' rotation for X, Y, Z boss since they likely won't ever get to X, Y, Z boss.

(c) Optimal gameplay is not needed in all cases, only in those requiring performance-level gameplay, like dedicated raids.

(d) One should demonstrate some minimum level of consideration for others when playing with a random group.
When people are playing dungeons, they hopefully, and typically seek to clear the dungeon without too many wipes within a reasonable amount of time. Adapt to the needs to the group as long as the objective can be done; big pulls - more heals, small, manageable pulls - a little more proactiveness. In most cases for lower level content, a savings of 3 - 5 minutes can be expected on a 25 - 35 minute run. Most people don't usually notice this anyways as they are busy in a queue or AFK or doing something else while in game. No one is 100% efficient as a player in setting goals and completing those goals. Anyhow, horseplaying and pulling all the mobs or just simply not healing and not damaging mobs is a demonstration of showing no consideration for others towards completing said objective. If someone is at least healing, they are at least contributing. People who have this expectation of being down to the last second in dungeon savings to go on a 16-hour grind on a weekend are unrealistic and need to re-adjust their own expectations, and to see if they are themselves that 'optimally attuned' to achieving their goals - chances are they are not.

With all these factors in mind, at the end of the day, it is the player who decides whether he or she wants to improve his or her level of gameplay to spend less time idling and more time being proactive. Some people enjoy doing a concurrent analysis while playing, positioning of mobs, timing of cooldowns, the proper setup or contingency plan for when X, Y, Z member fails and whatnot - while many also do not. The average level of gameplay or skill that is needed in low level content is not a requirement to be optimal at all times. Players choosing to do group content do have objectives, but realistically, dungeons won't take 1 hours or more (2.5% percentile wise) when everyone is playing at said 'average skill level'. To this end, we don't need to encourage 'not playing at all - or being inconsiderate' nor do we need to make everyone 'optimal raid-master machines that systematically play at the 99.9% percentile level'.

If you can heal and DPS, and you want to be better, then do it.
If you can only heal, and don't have the aptitude or capacity to be better, then it's fine. Just don't expect to do harder content where the standards are higher.
If you see others that heal and DPS and no one is dead, great, they are doing better than average or perceived level of average skill.
If you see others only heal, and everyone is alive, good - they are doing what contributes to the objective of said dungeon, although there is room for improvement, if the player decides they want said improvement. If improvement is necessitated to clear said content, then help the player improve. If the player refuses to improve, great, you can remove them from the group.
If you see others only heal, and someone still dies, and it's not because they are new, and not because the party members decided to stand in orange AoE circles, then give them a few pointers.

Give someone the benefit of the doubt.