I would consider it to be a disorder because from when I was diagnosed, there have been times when I haven't felt like myself, that I had no control over whatsoever and these are things that can be controlled by a 'normal' person but an autistic individual would struggle over these actions. I'm not saying what, but it is something that a normal person would consider an inhumane or consider you to be heartless because you don't feel any interest in them.
A normal person can overcome these things, autism is a barrier which cannot be broken, it is a lifelong disorder which affects your ways of life, learning and interpretation of information and may draw your mind to do strange things or say things in ways people wouldn't understand.