This is going to sound stupid, and I apologize, but as an Undead player I love the fact that I can swap to a dwarf form and throw down a petrify to temporarily lock out an opponent in the middle of a melee.
I think they decided to make it "in line" with the Petrifying Visage/Medusa Head polymorph ability.
It is certainly not on par with Petrifying Visage, because while they both cost 2 AP, Petrifying Visage affects all enemies in a 15 meter radius, whereas Petrifying Touch affects a single enemy within a 3-4 meter radius, and does significantly less damage, too.
I think that it should be in line with the other racial skills. If you love it now, just imagine how much you'd love it if it only cost 1 AP.