why were the dothraki mad at Dany's death?

[Dex drako]

I'm confused aren't the dothraki a "keep what you kill" society, so then why were the dothraki mad Jon killed Dany?

by all right the dothraki should have hailed Jon as they new leader or since Dany make them all her blood riders they should have all killed themselves. it makes no sense they'd turn against Jon for doing exactly what they feel a good leader should do. which means it was only the unsullied who should of wanted to kill Jon and there isn't enough of them to really matter.