I can believe that ancient japan would have invented a computer if given sufficient time in some alternate reality. once the appropriate questions had been asked and answered of course.
The real issue is not whether Japan would have invented a computer in an alternate reality, but whether we have invented it in ours, and whether what we call a computer really is what we perceive it to be. If human reasoning was fundamentally incorrect, we wouldn't be able to detect it.
humans from different cultures will sense many things the same way. a small black dot will be a small black dot and so forth. likewise, i can believe that ancient japan would have invented a computer if given sufficient time in some alternate reality. once the appropriate questions had been asked and answered of course.
I don't see the same thing for morality though. Or at least not to anywhere near the same degree.