I am going to try to explain where "these looting 'rules'" come from. Please don't misunderstand this as me trying to justify these rules being the best under most circumstances. I am not.
The BoP loot system creates a Prisoner's Dilemma (that gets repeated over and over within a certain group of participants, too). From that point of view, it is easy to see that a fixed group of people playing together (such as a guild, typically) with the goal to achieve "best possible equipment for all group members" is going to reach its goal a lot faster if the individuals in the group are not "greedy". So, if any item drops that more than one person would use, the one should get it, whom it means the biggest upgrade for. For the others, this may be a temporary disadvantage, but over time everyone will get ahead in equipment a lot faster.
Thus, idealists will always let the most "needy" group member have the item, even in pickup groups, helping to get the whole server the best equipment fastest, in theory (presuming that all others are idealists too...).
Non-idealists, if they think ahead, will still act like that in a group of regulars, even if it's not for their own short-term best. Sometimes they will even act like that in pickup groups, for example if they deem it likely that they will meet up with the pickup people again in the future (let's say, for raids).
Short-sighted people or people who don't even trust in their relationships to the people they play side-by-side regularly (or people with totally other goals, see below) will of course maximize their gain by just rolling on everything...
Ok, I want to state again that this analysis is only strictly valid if you have the goal to achieve best equipment fastest. But people always have a wide range of other goals, like having fun, or collecting gold just for the heck of it, or making lots of friends, or being famous or whatever. All these other goals may influence the looting rules someone lives by, consciously or not.
It is also only strictly valid in an environment where you will meet the same people again somewhat reliantly. And, finally, it is not necessarily the most "fair" set of rules, depending how you define fairness/equality.
Ah yes, and managing a guild is always something that will cost a lot of time and dedication, in my experience. If you "just want to play the damn game", Draginol, you should probably resign from being guild master (I hope that doesn't sound too harsh, it is not meant like that) or maybe get good 'advisors' that handle the social stuff for you. I have met people (few though) that view exactly the disputing and sorting-out stuff as "the damn game" and have a lot of fun with it (and really care for getting it right). These are the ideal guild masters imho. - For others, leading a guild can quickly become totally overwhelming. I have led a guild one time for several months, and I have learnt the hard way that I belong to the others, the ones that have more fun playing the "damn game" and not the damn social meta-game.
Addendum: If you don't know about the Prisoner's Dilemma (I guess lots of readers here do, though), I highly recommend reading up on it. Very interesting stuff, imho.
