"Casting an evil-aligned spell is an evil-aligned action" only comes into play once the individual campaign setting has been chosen.
The Pathfinder game makes lots of assumptions about the individual campaign setting. The whole fire-and-forget spellcasting concept is a big example.
This particular assumption is one you don't like, and (probably) wasn't explicitly there until now. Like most such assumptions, it can be avoided or worked around, even more easily than fire-and-forget spellcasting can.
[And, as a side note, thank you to the 3PPs, and occasional Paizo material, which help me avoid fire-and-forget spellcasting: psionics, spheres of power, the kineticist, strange magic, and I'm sure there are more I'm forgetting. I love alternate magic systems.]