Blizzard should consider having strongholds as End game content

Why aren't Strongholds end game content as nightmare dungeons?

Doing the rogue to lvl 74 and having two alts, the Strongholds, are way more fun than dungeons. Since if you start the alt and you skip the campaign you see what you will be doing the entire game. Running rotation of dungeons / tree of whispers in combination or after 50 helltides.

When conquering strongholds there are so many things that are different : Objectives are clear, not much backtrack, smaller scope, see everything on map where to go, spawns are more centered. And it feels fun. most cases you have a boss fight at the end.

I just think that also strongholds should be repeatable, the same way in endgame that dungeons are