Why are people complaining about there being all these different sexual orientations? They're not invalidating your orientation by finding a label that suits them, they're just finding one that fits snugly for themselves.
So what if someone identifies as ace or demi or grey-a or omni or poly or pan or any other thing that they fucking want to? If one label fits better than another label then shouldn't the be allowed to use it? You wouldn't make a gay person label themselves as straight right? It erases them, they would never be comfortable in their own skin and they'd be constantly confused because why are they attracted to their own gender?
If someone wants to identify as one of the lesser known labels let them, it allows for diversity of the human race and lets someone identify with a group of people who experience love the same way they do. There's no crime in that.