One would think perceptual dysfunctions would be sufficient to define the condition since the inability to discern or perceive phenomena and failure to execute or adjust behavior due to lack of proper feedback could explain most if not all characteristic behavior
Unusual gestures and speech, improper social behavior would be explained by the inability to fully discern speech and gestures and learning them in a partial manner while repetitive behavior and rigid thinking would be explained by a limited range of feedback causing a failure to diverge. Even the stereotypes like lining up cars by color, spending hours watching washing machines spin, being really obsessed by specific sorts of machinery etc. can be explained by low-level patterns like color gradients, mechanical movement etc. registering much more dominantly than higher-level patterns with a larger number of elements and chaoticity.
I don't see how Occam's Razor would not apply here. What makes it necessary to define autism in such a nebulous way then? Is it the history behind it, or is it more nuanced than I think?
Edit: I should clarify, by 'perceptual dysfunction' I am speculating about a more general form of sensory processing disorder. There is no reason the mechanism behind sensory processing disorders would not affect perception of higher order emergent phenomena in the same manner.
For example, think about a chain of emergence like
points -> curves -> shapes -> faces -> expressions -> nonverbal messages
With sensory processing disorder in my example shapes might fail to register or dominate and disturb perception at a noticeably higher rate than without. I believe the same can also apply for a 'perceptional dysfunction' where faces, expressions etc. have a higher chance failing to register with or without disturbance in perception of lower level patterns.