I think AS is like any other mental illness or disorder (yeah I know it's not a mental illness before anyone jumps down my throat, but it's similar) in that everyone has "symptoms" of it to a greater or lesser degree, it's just when it has a big effect on your life and limits the way you can live your life that it becomes diagnosable
For example everyone gets shy now and then, doesn't mean they have social anxiety disorder
Everyone does little things like checking stuff or counting, doesnt mean they have OCD
Everyone feels sad sometimes, doesn't mean they have depression
and when I say everyone, I guess I mean almost everyone, as I'm sure there are some lucky people who never get shy
But yeah, with AS, plenty of NTs get obsessive or misunderstand things or have weird sensory problems. It's when all these symptoms come together and limit your ability to live a normal life that you have aspergers or autism