Those of us that regularly run a DPS class or spec know what it's like to live and die by the meters. During progression when you're running up against enrage timers or having trouble getting adds down in time, Recount (or Skada) becomes the judge, jury and executioner. When the fight is going on too long and your healers just can't keep up with high amounts of sustained damage, people start checking the meters for those people who aren't pulling their weight. Even during farm content we are always competing with each other and jockeying for position on that little stack of colored bars in the corner of your screen.
We can talk about sampling bias and how the best parses in the world are coming from the best warlocks in the world and the best warlocks in the world will play the best spec if it gives them any advantage, but let's face it: you have to be stubborn or stupid to play anything but Affliction right now. Destruction and Demonology aren't bad specs by any stretch and can perform admirably in practiced hands, but both are firmly in the middle of the pack. Meanwhile, Affliction is at the top of the simulated mountain (Arcane is currently an outlier and more of an anomaly than anything else). Raidbots backs up this information by showing Affliction parsing higher overall than any other spec in the game in every single raid mode. According to SimCraft, realistically with some practice and a little bit of gear tweaking, a Destruction warlock like myself can see an 11% damage increase simply by switching specs. I wouldn't need to gather an entirely new set of gear like an Enhancement shaman going to Elemental or a Balance druid going Feral. I would simply need to visit my class trainer, rearrange my action bars, and spend some time at the training dummy.
So if that's the case, why am I still specced Destruction? I'm either stubborn or stupid. Possibly a bit of both.
I've had a long and passionate love affair with Destruction since the spec was revamped in 4.0. I enjoyed some time in the spotlight early in Cataclysm when the spec was the flavor of the month, but I also stuck with it throughout Firelands and Dragon Soul when Affliction and Demonology took their respective times in the sun. I'd tried switching to Affliction when we were having trouble with Heroic Staghelm but even when I was dominating the damage meters in my guild I still didn't enjoy the spec. I spent some time with Demonology as we started working on Heroic Spine and Madness and it became clear that Destruction just wasn't going to cut it. Again, the spec never really clicked for me and the entire experience was mostly an exercise in frustration. Unless a fight is designed in such a way that Destruction just can't hang (or balance issues bring it down enough to just not be viable anymore), then I switch back to Destruction at the first opportunity.
I enjoy Destruction. The idea of being a zany, twisted Pyromaniac that runs around finding new ways to blow crap up with chaotic and unstable energies appeals to me (which is odd since I first rolled my warlock because I liked the "life-sucking-Sith-Lord" theme of Affliction). I love the fast paced nature of the spec and churning out 3 Incinerates in the time a Demonology warlock might get out two Shadowbolts. However, I also enjoy downing new bosses and getting shiny new purples.
We're behind in our progression right now. 5.2 is on the horizon and with it a new raid tier. Instead of working on hard modes and getting prepared to hit the Thunder King square in the tenders, we're working on Lei-Shi and have yet to even pull Amber Shaper. I typically swing anywhere from the middle of the damage meters to the top, depending on the fight mechanics, but when I see a former guildmate outside Heart of Fear wearing Heroic gear and sporting his Soul Shards around his head, I have to wonder if my stubborn refusal to change specs is the reason we're not progressing as fast as we should. We haven't had too many problems with enrage timers, but dragging a fight out unnecessarily by being a suboptimal spec only leaves more opportunity for healers to run out of mana, tanks to run out of cooldowns or DPS to die.
I'm either stubborn or stupid. Probably both. It's been a long, fun road with Destruction but maybe it's time to move on.