Because not everyone is able to get those hints. I literally just said this.

If you’re being a dick to everyone while showing zero interest, you do not get to whine about how you are treated. It is as simple as that. You are treated by how you behave and this behavior is shitty so it’s treated shitty. No. There isn’t an excuse that will allow someone to get away with this behavior fully and without crticisim, no matter how hard you try. People are responsible for that actions.