It is not broken just because you don't like the play style is the main point.
Go get a Fate of the Fell then and run around Shotgunning every thing to death. Or get Schaefers Hammer and run around thunder hammering with a lightning build-out. Go get a Foote and throw shields in Holy dress-out. There are other options. BoP Condem was taken away from us, so increased damage AC is what we got in exchange.
FIrestrater is weak in T5 and T6 solo play... by the time the DOT stacks high enough you are dead from the Blue Champ pack (unless they happen to have the damage type of your selected immunity necklace). Crusaders aren't super bursteee. It is steady and slow... which means most of the time you almost have to have the Wrath reduction (shotgun them to death before they get you) or the Prophet (50k+ Armor) for highest Torment.
WTF -- a class gets a good ability (but loses another -- Rally) and the Diablo dolts come out and post stupid things like:
@ Wahsi "Firestarter is broken, so for the moment perma AC is the best way to go. By broken I mean nothing compares to it. You can spec lightning and use thunderhammers, but still firestarter will be half your damage. That's how absurd it is."
Comments like that are plain dumb. Do you play a Wizard and say Archon build is broken? Do you play a WD and say Larry-the-Giant-Gargantuan is broken? Nope, than do us a favor and keep your comments to yourself. They confuse and add more noise to the chatter about current Crusader state of affairs. Firestarter is actually a fun play style, but has a huge down side also, which is you are weaker for hard T5+ content than say a Prophet AC.