There seems to be a couple of issues cropping up in here that are making this entire discussion go in a circle. First off this game is pattern memorization. iLvL is a whole different barometric and while it does effect the outcome of a fight, it does not fully determine how much pattern memorization an individual has done in the game. Even Titan Extreme mode is largely a pattern memorization game, which is why people who have done the fight through a ton start saying it is doable while for those who haven't started or beaten it yet say it is impossible.

So yes, iLvL does not determine solely how effective a player is at the game. However, the iLvL does determine what content a person has the ability to access. It also determines how difficult a fight will be to complete because the closer someone is to the minimum gear score, the longer the fight will take and the more time there is for people to mess up.

Another factor is how well a given player has learned the basic rules of play in the game: Does he realize he needs to move out of red ground patterns? Does the player in question know the correct order of abilities on his action bar to maximize his effectiveness?

Finally, there is the players physical and mental condition. If someone is coming back from a long day at work and are mentally exhausted, the chances of them completing any challenge in the game is going to suffer. This is why in general it's not the best idea to be spending hours and hours smashing ones head on a fight for days on end, and just to focus on a few good days where people aren't feeling like they are mentally battered.