I agree with that. The issue is that for an increasing number of players, required MSQ content is becoming an unwanted irritant rather than an enjoyable part of progressing the story. (This is more true of solo duties, IME, but let's leave that discussion to the quests board.)
I realize some people would be delighted if the bottom X% of players in PvE skill would simply go away (something I suspect is already happening), but for a game with such a multi-faceted, broad-based appeal, this strikes me as a shame. And where does it end? Do we keep moving the bar up so that eventually only Ultimate raiders find the MSQ dungeons interesting? I also think such conversations have sharpened recently because of the severe drought in non-raiding content.
I'll also accept that many players who currently struggle with PvE could improve at it, but you'll never wipe out differences in skill entirely. So in order to accommodate those who are bored of the simplicity of MSQ dungeons, while retaining those who struggle, I've suggested SQEX needs to take a dual-track approach.
FWIW the only roulettes I do are Frontline because I enjoy it and MSQ occasionally when mogtomes is going on. That avoids me inconveniencing others. I don't need the current tomes for anything, and agree with you that the OP's complaint about expert roulette is a self-imposed problem.