People have only been complaining about the 5 second CD because that’s just easy pickings. They could make it a 60 second CD and people would still complain about how “oppressive” Brigitte is.
It’s not the cooldown that’s annoying, it’s the fact that her stun is tied to her shield, which means it’s a melee attack so there is no shielding from it, and she can use her shield for cover before, during, and after the stun to get in and out without taking damage. The problem is, it can get tricky to actually fix that. It’s really easy to either make her viable but too oppressive, or not oppressive simply because she isn’t viable. Blizzard’s going to have to tote a fine line with this one.
Also, as a side note, the bash does 50 damage. It’s the whipshot that does 70.