I have never seen anyone being stunned for so long, because they blocked, that he couldent block the next attack again.
What happens (at least to me):
-I block
-get stunned
-don't realize I'm stunned, so I try to counter-attack
-No attack occurs (I'm thinking "this must be lag", so I keep mashing attack button)
-I don't block, because in my brain, I'm thinking "it's my 'turn', so I get to attack now"
-I die
Having to block twice in a row without getting to attack in between is a rare enough occurrence in crpg that it totally throws most people off their rhythm. It's not like knockdown where you're like "oh, I'm on the ground, I can't attack now", the cues that you are stunned are much more subtle. By the time most players realize they are stunned, it's too late to switch to a block.