In AD&D 1e, "10% of Half-Orcs can pass themselves off as the other half." I don't know if later editions revisited this "racial" trait. Still, these half breeds are taking a hit to Charisma; even if they do look human, it's an unattractive Human (most of the time).
I'm just going to quickly point this out : one can have Charisma without being considered physically attractive. Physical attractiveness can play a role but so do things like commanding skills, diplomatic skills, persuasion and deception abilities and so on.
That and, yes, as mentioned by others, beauty is subjective. There are plenty of players who have the hots for non-human characters like orcs and giths, or even humans that don't fit some beauty standards (also, there a plenty of different beauty standards, depending on time period and location, different cultures exists).
Here is an interesting reddit thread on "Charisma ≠ Beauty", including quotes from ealy version of D&D.
Last edited by MelivySilverRoot; 24/11/2212:38 PM.