I don’t think there is any real valid complaint about the new Call to Arms system: the reward bags, which offer a chance at rare mounts, are bind to account, meaning you can send it to any character you choose on your server after receiving it.
If you are a DPS player who thinks the additional Call to Arms system is unfair, level up a tank alt. You can send the rewards to your DPS main. I don’t think that “the rewards are too much, but not enough for me to play a tank” is a very strong argument against this system now that you can put them on any character.
I personally will be tanking a lot now and working on getting appropriate gear. I’ve heard from a lot of raid-geared tanks that they queue as DPS (since its so much easier and they can do other things while in the queue) or don’t run heroics. This system can entice great tanks into the queue. Yes, it will entice new tanks, but tanking takes time to learn. You can’t soundly say “we need more tanks” yet “we don’t need any new tanks.” Would you put up with new tanks for a 15 minute shorter queue? We have no idea on how this will pan out – but all the negativity around every change Blizzard makes is getting old.