You're moving the goalposts here.

You started off with saying that there's no value to login names beyond ASCII, and now you're (a) insinuating that anyone who would wish to have login names beyond ASCII are too heavily invested in their login name, and (b) there's technical downsides to this.

Point b is certainly valid, and the whole reason there's a discussion in the first place. Point a might be true, but very different from what you originally wrote. And again, I suppose, this doesn't apply to you, because your login name – which you isn't attached to at all – is naturally ASCII safe?