I agree with a lot of what you are saying but the sticking point for me is this: "being carried".
So rant mode on:
I disagree with the idea of being carried if you are undergeared in this sense: if the team would fail without you, it doesn't matter that you required an above average healer to keep you up, you were still contributing. Not as much as perhaps is ideal, and yes the healer contributed more than usual, but nevertheless.
Carrying implies you might as well not be there: in my experience whenever this arguments comes up "oh you only did it because you were carried" the person in question still contributed to the fight. Just not as much as they could have.
I have seen the cases where a person was carried, I have been one of those people. And there is a huge difference between the time I was dead during every boss fight in cutter's cry (as healer), and the times where I could barely keep anyone alive because I wasn't geared enough but we won anyway.
As a healer (I don't know if I am "average" or not. I usually think I am fairly bad, but I am obviously my own worst critic) I have definitely seen both cases on the other side as well. Where I just left someone down because it would be a waste to res them, and I could ill afford the MP. That was carrying. We won without. Other cases I keep a person up with a lot more effort, but we couldn't have won if I hadn't. Because that person contributed.
The difference is this: one is being carried because you are literally useless, and not contributing anything, the other you are making things harder than they could be but still contributing to the overall success of the party. There is a difference, and people need to stop confusing the two because it just makes the whole argument worse.
As far as Titan: I agree first timers should probably try to get the best gear they can get. Once they get it down however the actual requirements drop. Not as much as most dungeons (because of HP), but a fair amount. Why? Because within the limits of what is possible, skill trumps the gear. Which is the whole argument people keep missing here.
And as someone else above mentioned, I have come across players who were amazing, more than holding their own, while being ridiculously under geared. Not to mention that this attitude of gear requirements and levels and "carrying" dismisses them sight unseen, and is part of what makes end-game so potentially toxic to new players, no matter the skill level.
Anyway end rant. (Also this whole argument completely misses the point of the OP, and is a bit of a distraction. So..)