I personally like Emergent Leaders with unique traits, like Nightmarish and Butcher, so it's a bit of a shame to see those leaders go (even if I never did use them - but only because I haven't played their civilizations). Tethira is probably my favorite Bannor leader, for example. The ability to offer something unique on top of the ability to essentially pick a second trait of whatever you want allows Emergent leaders with unique traits to be both interesting and dynamic, which I enjoy.
I am, however, all for the removal of leaders that add absolutely nothing to their civilization, like Melisandre - I doubt anybody would ever actually play as her, so it's really no loss.