Sad experiences of a newbie

[Ilyrian]

And at level 53, he/she spent enough time in dungeons to likely take repeated lashings for not DPSing.

Really? That has not been my experience - well ever. Pre-60 I have never seen a healer be called out for not dpsing - even not being particularly great at the actual healing part is more likely than not to be tolerated given that the player is new.
If a Sprout healer can keep a tank up and the party healed that's more than enough in leveling dungeons and I would say the vast majority of the player base is just happy their DPS queue finally popped.

The OP had given no actual information about the situation other than he's had bad experiences healing in DF.
6 pages of arguing about speculation is mad - and achieves nothing.
Maybe he's not good at it. People do get mad at healers - it's noticeable when they aren't great; that comes with the gig.
Maybe he's taking more time to adjust to it and will get better - too many maybes to be having an argument on his behalf.
@OP I think you must have had some very bad luck if your first impressions of FFXIV were so negative - that it a shame. As other have said, perhaps you just need a bit more time to adjust to the style of healing - it is very different from other MMOs (as you said you've had experience before).
We all need players willing to heal so hopefully you'll stick it out and feel comfortable: when it clicks it clicks. If it clicks.