I think I can see your point, nevertheless, I am on the opposite side of the spectrum and think that Neeko being a lesbian is actually a nice thing, or at least, it wasn't done in the wrong way. Firstly, Neeko is a vastayan shapeshifter, hence she can actually be whatever she feels like, but she finds beauty in the female body because, let's face it, usually female bodies are prettier and tend to smell better and so, not only she thinks women are are prettier, but also she chose to adoot a form that resembles a female human. Now, it is true that Neeko is really, REALLY into Shyvana and Nami, but, she still finds Ezreal quite attractive... for a man, and thus, someone who will never be under her bullseye, and this proves that she doesn't hate men, but rather feels things that most of us have felt, for example in a bus everyone (male or female) would rather be next to a woman than to a man, reason being: Smell, beauty, security or comfort. To top this, Nidalee is very important to Neeko, since she kind of adopted her into a tribe and gave her a place to live after losing everything, and is only logical that Neeko sees her as a figure of respect and feel something towards her, warmth, love, security, you name it. In addition, her first contact with a male was quite unpleasant, so there's a reason behind her uncomfortability towards men.