My point exactly! With so little dice and only a one in six chance of hitting, your looking at roughly 1 blast marker per 36 firepower, which is not exactly phenomenal. Matter of fact, from the lists I have seen, not many fleets can muster 36 battery to one side in a single squadron...heck, some 1500pt lists don't even have that much battery in a broadside across the whole fleet! Along with the fact that you remove 1d6 a round, the odds of blast markers sticking around to protect you with the models that the good folks of this forum are suggesting is...astronomically unlikely, at least in the first turns were it matters. Having to roll sixes is not a big issue, but having it count as ordnance allows almost no chance of effective use.
Perhaps if you could count it as something other than actual ordinance, as it is a lot easier to create a blanket cloud than hit a target. Although I don't have a number, I remember reading 1cm=10,000km somewheres. Assuming even 1cm=1000km (ludicrous), a ship is only a couple of km long, whereas a blast marker (3cm, I believe) is thus 3000km, or more likely 30,000km. Hitting a 20 meter fighter and a 30,000km should not be equally difficult, no? Just my two cents.