I think Flat Chest had the right of it earlier in the thread.
A lot of the fiasco is resulting around one subculture getting more attention than the other subculture, and the "unrepresented" subculture is lashing out. There was even an earlier 2013 (?) interview that stated that Male viera weren't really planned anyway: https://i.redd.it/ca1q5hg9ntn21.png
Don't think devs are sexist, or even homophobic. If anything, based on what the in-game world has set up, it's mainly racism that's an issue among the IN-GAME (keynote: IN-GAME) characters. For example:
Gay marriage? A-OK.
Having multiple relationships at once? Go right ahead.
Interracial relationships? Looked down upon.
A combination of two or three of these? Probably ok, honestly.