1) If we assume that it's essential to genderize pronouns, it doesn't really matter what the majority fits into because existence of other options does not influence that majority at all. The only case where it matters is when someone doesn't fit. The utility remains unaffected (in fact, it actually is increased because of better expressivity).

2) If we assume that it's not necessary to genderize pronouns, then it may be argued that we're losing some information that the vast majority of people was comfortably fitting into - but I don't really understand why do we actually need that information. When I refer to other people, it's extremely rare that I do it in a context that requires me to mention their gender identity (or even what do they have between their legs). In those rare cases where it's actually relevant, I wouldn't mind having to express it explicitly at all, so overall the utility seems dubious.