Zero,
Firstly, you forgot the 3rd way of life - that of the neutral person.
Many are quite capable of living relatively neutral lives. Everyone will
have their selfish moments, but with a bit of restraint and adhernace to
the principle of "...try not to harm them cos they might just turn
around and kick your sorry ass..." neutral people can live pretty happy
without being too evil.
Of course, there are always opportunists, who turn evil, and then (as
you said) the need for "good" arises. And of course, good without a goal
(evil to oppose) stagnates. Such is life

What you said about good being evil by driving you to kill the innocents
to lower your alignment is much like the "who came first, chicken or the
egg" paradox. After all, delivering you into a stockroom and
slaughtering you is both a good way to destroy the evil that is you AND
a good way to make you want to lower your alignment. There are two ways
to end this paradox:

(1) Skarash's method. Let them summon you, then kill all 6 of them on
your own, even if they DO happen to be 6 of thje strongest the Light has
to offer at the time
(2) Those representing the Light could remember their real purpose,
which is to prevent evil, not just destroy it. If something they're
doing is perpetuating evil, they damn well oughtta do something about
it.

Anyway, the moral is that I cant quite decide whether I agree with you
or disagree. But one thing I DO have to say is that (a) some probably DO
enjoy the screams, even though you may not, and (b) necromancers have
other reasons to have low alignments, such as deathaura and decay
effects.

Caled

Penned by my hand on the 11th of Daedalan, in the year 292 AF.