system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] If Snape had already accepted the morality issues about killing Dumbledore, why wouldn't he create a horcrux?

Harry would have seen it in Snapes memories at the end, found the horcrux, and brought snape back to life to thank him.
gpt
Because creating a horcrux involves incredibly dark magic, sacrificing a part of your soul, and things so horrible that people who hear the details feel ill afterwards.

We don't know how horcruxes are created. We know murder is involved, but that is all.

Also, the horcrux must be created by the person who is going to become immortal. Harry couldn't make one for Snape, since it wouldn't be Snape's soul filling the object, but a fraction of Harry's own soul.

In addition to this, if the owner of the Horcrux feels remorse for the act, and Snape regretted killing Dumbledore (Even if he understood it was necessary, he didn't want to), the horcrux would fail and he'd regain his soul with a nearly fatal amount of pain.