I agree that Cata raids were too difficult, especially for the x.0 tier, but I disagree that fights should be tuned so 2-5 people can be carried or covered for. In fact, that's the reason I couldn't stand 25 mans in Wrath and play strictly ten man: everyone has some level of responsibility. Being one of those last 3-4 dps in a 25man was boring, I felt I could go barrel off a cliff or go get a sandwhich and 90% of the time it wouldn't matter.

Were a lot of these Cata fights quite unforgiving on the individual level? Very much so, the individual margin or error was very small and it often only took one goof by one person to wipe it for everyone. That being said, I don't think that taking the fundamental idea away or tuning the fights to allow people to be carried is a good fix.

Individual responsibility is good, it adds depth and allows every player to feel like they command the fate of the fight (for better or worse), it just needs to be implemented in a way that if your average raider ever gets within 10 yards of someone or is two seconds late on an interrupt or movement it doesn't wipe the entire raid.