How would one design a raiding endgame which would not be a closed club? Samus describes the current situation: "Current raid design is based around individual mistakes leading to full scale failure for everyone. This is obviously going to lead to the exclusion of people who are more prone to mistakes. This is what raiding IS. The entire concept is high level perfectionism." As he says, it is blindingly obvious that any activity where you are supposed to be perfect ON YOUR VERY FIRST TRY is bound to end up a closed club. The solution is equally obvious: Create raid content with a margin for error, so people have the opportunity to train up.
Unfortunately there is a lot of polemic from hardcore raiders, which feeds the perception that they want their club to be a closed one. Any suggestion of easier entry-level raids is greeted with howls of "you just want easy epics", which couldn't be further from the truth. In fact I do think that the current plan of Blizzard to nerf existing dungeons is a rather bad one.
I propose the following raid concept: Average players run normal dungeons, which give them the equipment to start raiding in normal raid dungeons. The first normal raid dungeon is designed to be easy enough for at least 80% of the total player population to be able to succeed with gear from normal dungeons. The first raid normal dungeon is also designed to provide gear (and if you insist that gear can be colored blue) which enables the players to have an 80% success rate for the second normal raid dungeon. And so forth. Hardcore players run heroic 5-man dungeons, which give them the equipment to start raiding in heroic raid dungeons. The first heroic raid dungeon is designed to be hard enough for only the top 10% of players to succeed.
This concept keeps an air of exclusivity for hardcore raiding. But it also makes the raiding content accessible to the large majority of the players. And somebody who actually has a chance to raid without being perfect from the start will learn how to do better, and in the future maybe be a potential candidate for more hardcore raiding. The goal is NOT to make even the worst possible player to be able to beat the hardest content in the game. The goal is to give everybody access to SOME form of raiding, because you simply can't expect people to learn how to raid without raiding.