I don't know why this isn't a higher priority with you guys, or what's holding you back from doing it.
I'm sure people are fine with having the website and dashboard in English, but how much work could it possibly be to have just the registration page translated to other languages (other than the already supported languages)? I.e. internal views (admin) in English and external view (visitor/attendee) in the local language.
I work with translations myself and I'd wager translating all the labels and buttons would be about a days work.
It doesn't look good when you have the event title and description in, for instance, Swedish and all the fields, labels and buttons in English. Having it in the same language would certainly help with credibility, perhaps increasing the chance that a visitor will register.
Is anything like this planned for the future? Maybe you can involve the community. I would gladly help with translations to Swedish.