The true difficulty in CoP lied in just getting there, not in the battles itself. It lied in the fact that you were punished so severely for failure (loss of experience/levels, loss of items, gil, travel time, ect) that no one wanted to help out or risk a loss on a non traditional setup.
This was pretty much what I wanted to say. Besides the stuff you mentioned, there was the time involved in acquiring and storing level-capped gear, farming special items, and putting together a group. Preparing for a mission run could easily take all day. The prospect of losing all that investment, along with gil and EXP, was absolutely daunting.
I have no problem with high-difficulty missions. But what I'd like to see is either a reduction in the time and effort required to get
to the battles (to keep the time investment high there could simply be more battles), or some sort of checkpoint system implemented. For instance, once you acquire an item needed to win the battle once, it becomes much easier to get in the future. Once you've traveled through a long and dangerous mission zone once, you can warp directly to the end of it. Once you've beaten each part of a multi-stage battle, you can pick up where you left off.
That being said, I still respect the opinions of people like the OP who, as much as I might not understand it, love this kind of gameplay. If SE really wants to appeal to all audiences with FFXIV as they say they do, then they need to include both the casual five-minute stuff and the insanely hardcore CoP-style parts.
And frankly, I don't know if it really hurts anyone that much. By giving up on CoP, I closed the door to a few cool items and activities, like Limbus, but I never felt that I was missing out on anything fundamental to the game. What was at the end of that road was mostly more
insanely hardcore content, like Absolute Virtue, which really only appealed to the people who put up with the CoP missions in the first place.