Fai said:
Upon thinking about it, i think there's some dark secret about bankais that quincies know about, to be as desperate to seal them and get rid of users.
every war has two sides to its story, after all.
Well, a while ago I proposed a 'fourth stage of release' aka the same one as FGT.
So far you have to release your sword stage by stage, you can't just draw it and go bankai (Even though it might look as such for some since they can use their shikai without calling it once they know bankai). I'm pretty positive that you have to pass your sword from unreleased to shikai and then to bankai.
If a fourth stage do exist then by blocking bankai, they block any possibility of them going any higher than that.
I mean we are under the assumption that Ichigo and -getsu type sword are the only one that can use a stage of release similar to FGT but I don't think so.
The first shinigami ever to have been able to used Bankai might have stood out as much as Ichigo do now, I mean it was something new.