Bladestorm is by far the best talent. That fight was nearly designed for it and best of all; none of it is "padding". It honestly isn't even a competition.
While I understand progression = less focus on damage and more focus on mechanics, such as interrupts; I
garuntee there are better places to pick up extra stun/interrupt utility that your raid is not considering; ex: Tanks, Capacitor Totem, etc.
Most classes have atleast one interrupt and a stun of some sort, Warriors alone can AoE interrupt the first cast on all three targets and Storm Bolt a second, even Leap and Charge for a third!
If you are having issues with the interrupts I am certain you can swap the groups around a bit and make it work, its about both interrupting ability and balanced enough damage so groups aren't up too long (general rule is die before 3rd cast).
We carry a (dead) buyer each week and still manage to get all the interrupts/damage necessary, which is harder than you'd think even with gear.
The damage of Bladestorm MORE than makes up for the slight utility loss. It utterly destroys both Phase 1 adds and Intermission 1 adds, it annihilates Intermission 2 adds is the #1 MC breaker ability for that fight. It also is not a Single Target loss, so it doesn't hamper you through the non AoE portions of the fight. Win-Win-Win.
TLDR: Tell your Officer he is mistaken and should leave you to what you do best.
Source:
My #1 World DPS Garrosh kill on WoL
MY #2 World DPS Garrosh kill on WCL
(note WCL doesn't count MC damage, so the BS damage is actually higher than what you see, why I linked WoL first)