Right back to you - since you still do not tell us what this "lionshare of expansion" encompasses where you could just jump into the highets difficulty of raiding withing a week of being max level. So basically when you set up your point you were talking about the past..yet I may not?
Yeah..maybe you could "could hit icc within a week" - but for 25 HM? No bloody way if you wanted to pull your weight. And that is attacking your OP where you claim you could immediately hit the highest difficulty. You could not
Definitely not nitpicking when I need to remind you of the TBC attunements
https://vignette.wikia.nocookie.net/...20070207064601. You needed heroic 5 mans..gl grinding the rep to even enter them fast. Then you needed to raid to get raid quests to do further raids. Not to forget items from old raids to attune to the next raid.
So it is indeed only fair to point out x-pac after x-pac where your claim in OP was just wrong or exaggerated. You hitting lv 85 and your guild taking you to HM Firelands within a week? Yeah..I think not...maybe they needed especially YOUR alt and really, really helped you.
Then it is still only anecdotal evidence and nothing else.
If your point however is that AP and Essence hold your alts back longer now to really pull their weight...fair enough..we had that topic to death. Maybe Blizzard changes that after all the complaints. Maybe not. People are complaining already about anything that is in SL alpha. As they will complain if they see anyone get to their gear level within a week who just quit and came back while they worked for their gear in the hardest current content.