Yes. This right here is the reason every roulettes exists: To get people into old content they wouldnt do otherwise, so people who have never done it or looking for a specific piece of loot or want to do a certain dungeon/raid/trail for any other reason can get in. Its not primarly there for you to get easy tomes, but to fill those queues that wouldnt fill up otherwise. The tomes are you reward for being willing to submit yourself to a random dungeon.
They're not gonna break up alliance roulette. The reason the other roulettes are broken up is to channel more people into certain dungeons - right now that would be the recent level 70 dungeons. We're seeing a roulette for 50/60 content and one for 70 content. The 70 content is recent, more people need to run it, so we need to fill up those queues more. The level 50/60 is less frequented, so its okay that theres a wider spectrum of dungeons in it.
Come 5.0 we will probably see a 50/60/70 roulette - not a break up of alliance roulette.
First: Yes, imagine something in this game where you actually have to pay a bit attention and deal with mechanics! ...sorry, I dont mean to be rude, but "I cant faceroll this content!"-type of complain never sits right with me. More mechanics should be "do or do" instead of me, on my bard, telling me healer friend "You know what, I'm gonna ignore this one, just heal me up again" (and then having my healer friend slap a regen on me because thats enough to not only keep me alive but also get me back to max HP in a few ticks) - I'm not asking for savage in normal content, I'm asking for mechanics that you cant just ignore.
And second: How do you think LotA was when it was the current 24-man-raid? Do you remember the "jumping around the outside"-mechanic of that fist-fight-guy in ST? How often did you wipe to CoD in WoD because someone wasnt killing whack'a'mole-snakes? And when was the last time you saw those snakes? The same thing is happening to the HW-24-man raids - we're overgearing them.
Sooner or later we will overgear Rabanstre aswell - its already possible (and happens often enough) that you skip the snake-add-phase at Mateus. That Hasmalim only barely gets to summon the "split up"-sandstorms. That Argath jumps a way for his roomwide AoE with that one safe spot with less than 10% HP left.
But yes, til then Rabanstre is a raid where your biggest challenge isnt to get half of your party standing put on one platform.
You get your tome-stone reward as a reward for queuing up, willing to potentially deal with that.