“I didn’t mean to be rude- communication differences and Autism“, by Jeanette Purkis.  After giving a couple of examples, she writes:

The reason these misunderstandings occur is usually a differences in communication styles. There is nothing wrong with either of these styles, they are just different. The issues seem to arise when one group interprets the other as if they were using the same style. Sadly, due to these communication differences, we [Autistic people] are often thought to be unpleasant when we are not.

I am a very kind and respectful person. The idea of upsetting or offending anyone fills me with horror. I want my impact on the world to be positive. I want to help people and make their lives better. I am respectful and inclusive to a fault. The idea of hurting anyone’s feelings appalls me. So how do you suppose I feel when through no fault of my own I say something which is deemed offensive or rude simply because I communicate differently? 

It might go some way to explaining why Autistic people can be overly apologetic and socially anxious.