I still disagree. In the rare circumstance that the required roll results in doing damage, would you describe it as an attack, or the foe running into the blade?
Besides, many skip it, and when the roll is made, its "roll, if you don't fumble, lets move on." Not an attack, but a fumble check.
I think "Technically" covers all the ambivalence issues, in that you make a roll and it resolves as an attack, it's technically an attack.
The probability of an open ended high attack roll exceeds the probability of fumbling, so roughly twice as often as you fumble, you will open end high, so it's far more of a potentially dangerous attack roll than it is a fumble check, and you don't need to high open end. . .
A lot depends on the armor/attack table combo if the target is parrying you. . .because there are weapon attack tables that do hits at 15, and others that inflict a crit at just 65 (There are claw law tables that crit at 34). You're far more likely to roll a 70+ (31%) and chop someone for hits or crits through casual passive DB than you are to roll a 1-3 (3%) and fumble.
Our opinions may differ, but I feel like a +0 OB attack isn't casual, and either including it in a parry per RAW, or removing it as a house rule, isn't a casual change of minimal or no real effect on things. I think being allowed to make a series of +0 attacks is far more likely to kill or down one of your mob of foes than fumble you.
That might be a good thing, a more heroic style of play, but it's not a non change.
Vaske13/MarkC, in my RL experience, the best thing to do stuck in a melee is to backpedal in an arc, just as you said, and most of the punishing shots made are done from behind or the unexpected flank shots. . .I've never been in a real organized mass battle, but I'd assume there's a lot to be said for operating in a line with friendlies covering your flanks, and the line as a whole preventing attacks on the rear.