So Why do people like me?
Possibly because they also share the same prejudices. I don't know. I don't know the people around you. It might be because they know you have a disability and therefore maybe somewhat assume it's part of the diagnosis. Or they know that you're family and therefore you're stuck with each other and therefore they feel like they have to make it as easy as possible.
But you know it is possible to change your behaviour. Regardless if you're on the autism spectrum or not. But it does take work, hard work. I'm not happy about certain aspects of myself. I get into arguments, sometimes of the childish nature, online. I don't play the morally wrong person, in fact I do actively look for the arseholes so I can bloody well give them a hard time for once. But that's still not a healthy attitude. So I need to change that. It's better to do these things sooner rather than later because it reinforces a habit and as you bet older it's harder to change your behaviour, that's just a fact.
If you're thinking about this question may it's a sign to really try and better yourself. You're asking yourself an important question and it's on the road to change how you behave. Continue to ask yourself 'Why?'. That's what people don't do enough of, they don't look at things from another person's perspective or think they purely in black and white. Granted that is typical behaviours of an autistic person but it shouldn't ever stop you from trying.