Even people who do like you (platonically or otherwise) will miss this, aware of it or not. Struggling with this very much right now, thanks Sherry Turkle...Don't expect people who aren't into you to treat you with common courtesy. We don't live in that society anymore.
Here's the funny thing tho The more self-esteem you have, the easier it is to deliver bad news to someone else. The more self-esteem you have, the more likely you are to date other people with self-esteem. It's almost like the people who schlub you like that are schlubs, and if you don't want to be schlubbed, don't date schlubs. I recognize that the pool is often shallow, and we seek any port in a storm. But there are better people out there, and they treat people better as a matter of course. If you can convince yourself you're worthy of their attentions, you are.