Men are too often guilty of assuming that "hello" means "I want to have sex with you" Women think that because that is more often than not what it really means
I think both sexes can take it the wrong way. Me personally,I just see it as being nice,giving comfort and making one smile.I give ( and love to get ) "winks" or tell them "hugs" to men and women here, so unless someone flat out said to me" I think I want more than friends" then I think nothing of it!
You do realize that most people flirt for a reason, don't you?
Unless it's a friend and they know it's just a bit of fun it really is unfair to think someone won't assume you're hitting on them if you're flirting.
Personally, I'm oblivious and don't notice when someone's hitting on me until they tell me in plain speak, but considering that we're raised, trained and expected to follow largely non-verbal cues to direct communication giving people mixed signals like that and then criticizing them for not getting it is just cruel. The other party is not psychic.