Ah, the immortal hardcore-casual debate. Look, there are two kinds of gamers:
... and this guy.
Alright, so it's not that simple, but you get my point.
For many gamers, the greatest thrill is found in achievement; beating the odds, surpassing all obstacles, being better than your fellows, and (above all) winning. Such people don't just handle struggle, they embrace it. The harder the challenge, the greater the achievement.
For other gamers, like me, the greatest thrills are found in unexpected moment-to-moment experiences. While other folks are busting their butts for trophies and bragging rights, we're on the sideline enjoying hot dogs and cheerleaders. Sure, we're out to achieve goals to, but we're taking our time about it, going the scenic route, loving the distractions, and laughing as we tackle challenges in the most inefficient ways.
Why, oh why, do developers keep shoving us together?
Don't get me wrong. The best multiplayer systems capitalize on the existence of different playstyles by enabling cooperative roles suited to those playstyles. But it's ridiculous that matchmaking programs and other multiplayer systems rarely help players of similar gaming values to find each other.
Simply allowing players to check a box in your matchmaker for "hardcore" or "recreational" does not help, since everyone has a different understanding of what those labels mean. Simply enabling the existence of guilds for every type without helping players find the guilds that fit them is not enough. Sites like GamerDNA help, but only a fraction of your players will know about it or be interested in an account on a peripheral site.
I hate listening to another player tell me I'm suppose to play a class a particular way, complaining about the lack of coordination, bragging about what a badass he is, and so on. And players like that hate playing with people who don't stick to optimal strategies, who don't put in the practice to get headshots every time, who don't know all the slang and every scrap of knowledge about the game, people who laugh at defeat.
For Pete's sake, let us play with people we enjoy! When I log onto World at War on XBL and there are almost a quarter of a million people playing too, there's no reason we all have to be in the same match pool. More people would group in MMOs if they were not always having to roll the dice and hope this group won't be full of obsessive jerks or lazy idiots.