I was reading the spell Blasphemy and its got contradictory texts/
Its area for example says
Area nonevil creatures in a 40-ft.-radius spread centered on you
Then the spell effects
Killed: Living creatures die. Undead creatures are destroyed. Save negates. If the save is successful, the creature instead takes 3d6 points of damage + 1 point per caster level (maximum +25).
The subtype page for undead clearly mentions they are evil (howeve there is one case that is not evil, but juju undead are not part of this question)
Undead are invariably evil, as are the means to create such beings.
So since the spell isnt supposed to hurt evil things, why are undead destroyed?