Keep in mind that DKP systems can vary greatly. The simplest premise is that you get points for raid attendance, and you can spend those points on loot drops. But DKP systems are extremely customizable, from the manner in which points are gained to the methods for spending them, and whatever limitations can be placed on them.

A well-designed DKP system can eliminate many of the flaws/complaints against them. But any loot system will have its detractors. Officer assigned loot systems have to deal with accusations of favoritism/cronyism. Random roll systems can be very unfair (the old "player_A attended raids for weeks but player_B gets superEpic-01 on his first raid"). Need/Greed systems deal with accusations of lying or otherwise gaming the system (swapping in inferior loot to get a drop). Because DKP is so customizable, there is an endless number of ways for people to be unhappy with it. And poorly designed or managed DKP systems are a recipe for disaster.

Find some friends and build a guild of your own, then loot isn't much of a problem. That's what I did, anyway.