I don't think it's safe to deduce that there were few differences from the (perfectly valid) observation that there were many similarities. The problem is that the similarities all exist along shared dimensions (they typically wore two shoes at a time or none, just as we do) but the differences are found along dimensions that are not shared (Does their wireless plan include free roaming? Does your goiter make your cravat chafe?)

So looking back we see the similarities but are often blind to the differences.