I agree that a dub for Kara no Kyoukai isn’t a necessity, and I do think the Japanese dub is great. But, I also think a good English dub for the series would be a boon for English-speaking audiences (and the same thing goes for dubbing it in other languages, too). At least in my own experience, watching something in a language you’re familiar with, as well as not having subtitles on-screen, has an effect on how you perceive what’s happening. It feels more immediate, and things like characters’ emotions or the feeling of a scene come across more viscerally, which helps create a more emotionally invested experience for the audience.