Very skilled or “into it” dps players absolutely can maximize their trash or boss dps through their spec. In fact, you hear a lot that certain talents aren’t good for bosses because they do things like improve your down time, AE or survivability. But all of those things can be great for fast clears. Players also sometimes say (silly) things like how they only care about how they perform on a boss. But if you want to do something like the LK equivalent of a ZA fast clear for the bear mount, you need to be fast across the board, not just on the 4 bosses. Players wipe on trash too.
We’re not going to make crazy fights where we expect the entire raid to respec into something weird. That was even asked at Blizzcon and the guy in charge of all of the boss design said simply “No” in reply. If we can’t assume you have a warrior or druid tanking, then we can’t assume you have a mage with an obscure talent build or 12 healers or something else abnormal.
In heroic tier 11, there were 2 out of 13 fights that required only one tank. There were another two fights that encouraged bringing only one tank, but were tuned so that they could still be done with two. Some people complained that this was too many single-tank fights, and there was a relevant blue post that boiled down to "different fights are different" and said that we should expect some single-tank fights. This is fine. There was only one fight in heroic tier 11 where the idea of bringing 7 dps was even viable, and that fight was tuned such that you certainly didn't have to.
In heroic tier 12, there are three out of seven fights that require bringing only one tank. This on its own is a frustrating failure that leaves me scrambling to find things for my group's other tank to even do, and the only reason he's getting significant playtime in Firelands at all is because he also raids on another character. There's even one fight that almost feels like a zero-tank fight (Heroic Rhyolith), because your single-tank's role on that fight is so limited (stand in one spot, fight a spark, wait for p2). Firelands has made dps' role in the raid far more important and that's valid, but it's done so at the expense of mine. In the same way that many players refuse to tank, I refuse to dps. I don't have a single character with a dps spec, and I don't plan to in the future. I should be able to play the role I want to play in a raid just as much as the dps players should be able to dps, but heroic tier 12 is making it quite significantly more difficult to be a non-dps person without an offspec.
The same pressure appears to be present for healers. Heroic tier 11 did not have a single fight that specifically required only bringing 2 healers. My group 3-healed Sinestra even when it wasn't popular, and it was doable. Other groups 3-healed Heroic Chogall, and that was doable. People even 3-healed Baradin Hold. Heroic tier 12 however introduces the first raid boss in Cataclysm that cannot be 3-healed, and when this healer pressure combines with tank pressure at the same time it leads to bringing 7 dps to a 10-player raid encounter. The fact that it's required for one of the bosses is something seriously wrong with the boss, in my opinion. The fact that it's strongly encouraged for more than one of the bosses, in a tier with so few bosses in general, is something seriously wrong with the raid. Not every person in this game wants to play dps. I absolutely will not.
Many players often complain about a tank shortage. Requiring 70% of your raid to be dps in a 10man fits the description of "something weird", as Ghostcrawler put it, and this is certainly something that exacerbates that shortage. My raid's other tank is bored already, and I seriously dislike having to ask him to come in for trash and then swap back out when we reach the boss. That's not fair to him at all, and having to do it for half of Firelands is kind of outrageous. This is getting to be almost as skewed as 25mans are.
