I honestly don't see this problem. They had to learn it when they first joined, what is different besides not having rep and no longer having to worry about getting a virus? I personally would much rather have a virus free website.
Granted I already know how to do everything with the new layout, but I know its not that easy for some and I understand their frustration, but come on now, don't leave all the friends you've made simply because its no longer vbulliten.
I don't care about the GUI of any site, simply for the fact that I cannot change the code to suit my fancy. That being said, I understand the need for change and in the interest of security {now that's funny, something secure on the net} for all involved and yet I see the point/s some have made by their distaste for the changes implemented.
This site is huge and being so must adhere to a more strict structure in order to perform adequately for the majority, not everyone is going to like this fact, something that should have been foreseen and metered out more slowly, imo.
I would wager that most of the more vocal proponents against the new look are the ones who have seen "too many" changes in an industry that has been for decades only available to a select few, raising their concerns even more.
I personally have had to deal with issues outside of this site and it's taken up most my time and while this site was undergoing it's metamorphosis I ventured elsewhere and found a nice spot in which to hang. I now have two places to babble on with the like minded...which too me is a great thing.