Chaos Wins!

One major competitive drawback of 40k tournaments are their scoring methods. The typical RTT or GT doesn't use a simple win, lose or draw result and then award points accordingly like in Chess or Magic: The Gathering. Instead it incorporates "battle point" scoring where points are carried over from round to round and a running tally is given. Winning and losing is secondary to simply how many battle points are scored in each game. What earns battle points? Wins will almost always grant these, but losses do too. Ultimately it's up to the tournament organizer. Defined secondary objectives can grant points, like killing HQ's or certain force organization slots (what if your opponent has few or none of these?). Often the margin of victory is also employed. If you blow out your opponent you are awarded a much higher battle point total than if you simply edge out the enemy. In 40k tournament play, a win isn't just a win.

The problem with this scoring method is that it skews the meta-game. Certain army types will excel at secondary objectives. Other army types will not even if in a straight up match the army list proves competitive. Some army types and codices can massacre enemies far more easily that others, thus racking up larger margin of victory awards. Some mission types can thwart massacre victories and prevent this just the same. Because of these types of scoring players are punished from taking certain types of lists. Just winning is no longer important, blowing out your opponent becomes the primary objective and players will alter their play or their army lists to satisfy that. Even worse, players who are paired with lesser generals with uncompetitive lists are rewarded with a greater chance at blowout victories. Players who play against quality opponents are punished because not only are victories harder to come by, but when you do win the margin is usually much tighter. In 40k tournament play, playing good players can crush your battle point scores. Playing scrubs can send you to the final tables.

In 40k tournament play where battle points are present, you want to play an army that can table opponents completely, and you want to prey on lesser generals to rack up your battle point scores. Playing to win isn't good enough, you want to play for the blowout. Until tournament organizers change how battle points are scored, the meta-game will favor certain army types that have a propensity to massacre, favor certain generalship styles that reward reckless deployment strategies and encourage favorable tournament pairings where generals with win at all cost armies get a golden ticket to play incompetent players with suboptimal lists.