I agree. If undecidability (or some stricter but still off-putting set)in a given language means an extremely complicated compiler that would be a mark against it, but if it's just an obscure edge case or something that is already not possible in a normal language, then I really don't care.

I would, however, like to see termination analysis applied to code more often - e.g. rather like only accepting a pure function in an interface, this function must terminate but might not be pure.