Do you know why the average pf player is so bad?

[Shialan]

why was it still the subject of healer's struggling with it multiple years and expansions after it's release?

You answered this question yourself. The healers and or the group were bad and didn´t care about mechanics. But that didn´t make this dungeon hard.

I don´t get how people say that dungeons were harder. People just had to do mechanics.

[Sebazy]

I don´t get how people say that dungeons were harder. People just had to do mechanics.

When was the last time you saw a legitimate DPS check in a dungeon?

When was the last time you saw a dungeon boss that could genuinely snowball a fight into a full team wipe if someone was caught napping?

When was the last time a healer (Or even DPS) was genuinely at risk of running out of MP/Resources/Cooldowns in a dungeon which would invariably lead to a wipe?

When was the last time you actually had to watch your positioning for fear of agroing more trash mobs than the group had any chance of handling?

When was the last time you went into a DF dungeon knowing full well that a few wipes on some bosses were almost an inevitability?

Granted, some of these you can blame of Job power creep and the current wild abundance of resources, but some aspects of some dungeons were just undeniably so much rougher than the hand held by numbers garbage we get today. We see the occasional gem like Peacekeeper, but those are by far the exception and generally only in tightly synced dungeons.