[Possibilitas]

I've noticed that unlike in PnP humans' ethnic languages (Illuskan, Calishite Alzhedo, Mulhorandi, etc.) are not treated like racial languages and granted for free, but require expenditure of the intelligence-bonus-granted language slot. So for humans it goes as such: common + intelligence modifier granted languages = total languages known. Where it should be: ethnic language/common + intelligence modifier granted languages = total languages known. Is there a particular reason for this?