Preface: I have played a Flame/Flame tanker, 35 levels total prior to deleting him. Yes, deleting. Why? I like a challenge.
There are a few AT combinations out there that are the equivalent of "cheat codes" in the game. That is to say that playing them is SO freaking easy that the leveling ability of that character's track to 50 is vastly easier and quicker than most others. Other "uber-templates" include Illusion/Rad, Fire/Rad, the old /Regen scrappers, etc. How do I know this? Because I've played them myself. I currently have 16 "active" characters on two servers and a handfull of others scattered about, not to mention 190+ deleted levels. I mention this only because I want to emphasize I am speaking from an informed perspective.
Back to topic, "Burn" changes.
Welcome to reaping what you've sewn. Well, what a handfull of "PL meeee d00d" kiddies have sewn. The Flame / [Flame or Ice] tanks are undoubtedly the FotM template for the last couple of months. Why? Because of their unquestionable ability to PL by herding. Those players who want the most "power" for the least effort are gravitating to the Flame Tank AT for it's proven prowess at raking in the XP.
What I am not saying is that ALL players who have this AT are interested in the easy route. Many players have had their Flame Tanks since retail and some even since beta. But what I am saying is that in the last two months the number of little ones begging for "l33t PLz" on PI has gone through the roof, and in my observation, then vast majority of them have been Flame/ tank cookie cutter copies.
IMO Flame tanks are (and have been) more like scrappers than tanks anyway, based on damage output when you factor in AoE. Not entirely bad, considering (again IMO) they have to go outside their primary and secondary pools to get a full "tanker-like" defense (talking Tough/Weave).
But to stick one's head in the sand and complain that this nerf was unexpected is silly. Burn and poorly designed AI have been manipulated to turn PL-ing into an artform. Without going into the details of why I think PL-ing is a plague, I will say that I can effectively debate that point, and that this change was overdue.
What I would like to see is the Flame tank compensated for this loss of offensive power with a compensation in the Flame primary for defense. Herding 80 mobs into a small circle/stack and whacking them in short order is, IMO, not "heroic" or good gameplay. "Pf4t XP" yes, but good gameplay? no.
The fault is an oversight in both AI design and AT playtesting. As it stands, the "most XP for the least effort" cookie is too tempting for more immature players to ignore. The fix needs to happen, but there should be compensation to bring them back into the realm of a true tank.
I'd even support a change that kept the damage as-is w/ Burn, and simply changed the AI so that it was less easy to manipulate.
When I'm overpowered, I'll admit it (did it with my /Invuln scrapper, but still winced when the axe fell). I hope the Flame tank population can do the same and concentrate on suggesting an equitable fix.
If you deny Flame tank leveling is currently too easy (and I made it to 18 soloing with only Scorch and Combustion), try leveling a FF defender, a Mind controller, or an Electrical blaster on your own.
Many of the less mature players will flame me like I've just taken away their X-box and grounded them for a week, but hopefully we'll also see more constructive/effective balancing ideas too.
Kudos to the fellow above who pointed out that you can still be effective when teaming (imagine a controller just locking them in the Burn patch for you).
Cheers.