A couple of things here.

Certainly Tier 11 is easier now than it was due to the nerf, but that took six months. What you suggest is fine now, but many people I raided with got fed up enough before that, that they have stopped playing. So while it MAY not be an issue now, it was then, and that's part of what we are discussing. If what Blizzard is promoting is a mix of the Wrath and BC raiding model, that's fine, but that didn't exist during Tier 11. Also, considering they are introducing an new raid difficulty level in 4.3 (LFR tool) I'm not really sure that's what they are saying the model really is.

"I really find it amazing that so many people figure they can't have fun if they aren't doing what the high-end raiders are doing." - For me this is why I though there was normal mode and heroic mode. Let the high end raiders do heroic and the rest of us raiders do normal.

As to the level of difficulty of T11 currently, is it accessible? I'm not sure. I still feel like I could get a new person through more fights in ICC (even pre raid buff) than I could get them through in T11. Having done this recently with someone who hadn't raided, they quickly go overwhelmed with everything that was going on and told me they weren't likely to do it again. That's only one experience so it's hard to build an argument from it, but it's the only data point I have.

"For all the talk about Wrath being faceroll, how many made it past Mimiron in Ulduar when it was current? How many even saw Mimiron when it was current? I'd bet there are a lot more people seeing Majordomo Staghelm now, while it's current, than saw Mimiron while it was current. And that was in Wrath, the "faceroll" expansion." - Hmm, I wonder. From the data on Firelands it looks like a third or so of T11 raiders stopped raiding, or at least haven't been able to down any FL bosses. So I'm not certainly what you are saying is the case. Also remember Ulduar when current didn't have the raid id extend option so any guild with limited time had a hard time progressing all the way to Yogg (this was certainly an issue in my guild.) As to the Wrath faceroll talk, I've always thought that gets overblown due to a number of factors, Naxx25 being severely undertuned, 10s being tuned a tier lower than 25s, the ICC stacking raid buff, and the model of "only the recent tier is current".