Not to mention that some WoW dungeons are involved in the story as well, like in Legion for example.
And not all FFXIV dungeons are mandatory either. Some are optional, and why are they not different?
It's a weak ass argument.
The reason why they are easy and always the same is because they want them to be easy and always the same.
And that's it.
Doesn't matter if it's good or bad, there is no reason as to why it *has* to be like that other than decision the devs made themselves for the players the believe this content is cut out for.
Comparing WoW dungeons with FFXIV dungeons is fair. The target audience is different though.
They want easy cookie-cutter build dungeons that story driven people who play their game can do and use their character abilities for.
Because if these dungeons wouldn't exist, you are more or less never actually pressing your abilities.
Leveling just doesn't require you to do so. It's basically an arena and ever since Trusts have been included, it's no longer different from the usual MSQ quests that are instanced. You'd be hard pressed to even call it 4 player/small group content.
It's an extension of the single player experience with an option to co-op that part.