You know it's just a test from the mountain spirit, don't you? Kikyo on the cliff isn't the true one and the actual Kikyo is the heroine in these entire series.
Kikyo bit selfish first she willing to sacrifice the Shikon jew for her own happiness without thingking about what’s gonna happend second still the same always thingking of her own happiness shes 50 years gone. And Compared to kagome she is willing to sacrifice her self to see inuyasha happy with kikyo.. what ever she’s back as kagome to fix her own mistake in the past. Is’nt it?