The Difficulty Has Not Increased In Casual Content.

[Ameela]

See, the battle content IS for them because the MSQ is the one piece of the game everyone is required to do as there is not just battle content locked behind progressing in it. You want to craft and gather for new areas? You need to do MSQ. You want a house in the new areas? You need to do MSQ. You want new Triple Triad cards? MSQ. You like to collect music and minions? Some are quest rewards in MSQ.

MSQ dungeons like The Burn need to keep in mind the experience and skill levels of all players because those players can't enjoy the game in their chosen manner without it. And if they can't enjoy the game, then why stay?

I mean technically crafters and gatherers with no interest in battle content could just ignore everything MSQ-related from 4.1 until 4.55 and then burn through it in higher iL gear for the expansion, since no crafting and gathering content is locked behind the story after 4.0.