Beacuse it's not supposed to be a line battle tank.
It's supposed to sit in the rear with the gear and blow stuff up from miles away

Ideally place it behind some nice thick
LOS blocking walls.
For the record 12, 10,10 is average to decent.
10,10,10 is low :( The ork equivilent is 11,10,10 with vastly shorter range and power