Not entirely convinced that the /roll folks in this thread aren't simply being facetious, but I'll bite!
In the first place, the expectation that a certain standard of impartiality needs to be met is completely misplaced. Especially when what you mean by "fair" is just wild RNG in all its untamed glory. The entire case crumbles before it can crystallize into something even vaguely resembling a compelling argument when you consider how utterly unfounded this premise is.
The instant the Master Looter option is chosen, you're surrendering to some form of a Loot Council. Systems like EPGP and DKP can loosely be viewed as attempts by players to "automate" their Loot Council, where some degree of human prejudice is removed, and your system does the loot councilling for you based on the rules you define.
The expectation that you should be entitled to what you think is your fair shot at gear also falls flat in view of the fact that raiding guilds don't exist to feed your entitlement to gear. They exist to enable raiding in a scheduled and organized fashion, among players whom you can generally count on to meet some minimum benchmark of competence. You build guilds like these by using intelligent looting systems that absolutely are biased and heavily-slanted in favour of rewarding performance, conduct, reliability and loyalty - all the attributes in players that make them valuable assets to guilds.
Now this ended up being totally glossed over, but earlier in this thread, Gnimo made one of the most salient points in this discussion - any raid you attend with a guild is not just something that's happening "right now" in a vacuum. It's happening because the guild's infrastructure was functional enough to allow it to happen, and part of what went into building it was a loot system that rewards people intelligently. This is something that's evident even to veteran players joining a new guild for the first time as long as they have some appreciation of the effort that goes into running a raiding guild that has its act together. You join a raid, it starts at a certain time, people do their buffs properly, know the strategies that will be used for each encounter, the raid (typically) makes it much further into the instance than pugs do, and then the raid ends at a certain time - all of that is built on the back of the guild's prior raiding history, and the players that made that possible.
Also:
Yep, this isn't how statistics and probability work.