Peter's plans (whatever they may be - I totally peg him as chaotic evil, FYI) end up being impossible for him to achieve so he decides to pass his resurrection on to Erica instead as one last Fuck You to the universe and/or our collective brains.

Peter Hale is totally chaotic evil.

Alas, the show has come a long way re: valuing its main women and side queers more; this does however NOT extend to side women, or characters of color, AFAICT.