Boils down to frequent misdiagnosis, anything that produces sensory processing symptoms or even just symptoms that only seem to be sensory processing related (but actually aren't) can be misdiagnosed as autism, it's the same situation with ADHD, it's more often a misdiagnosis than an accurate one, so when a significant portion of autistics aren't actually autistic but were misdiagnosed then naturally that really muddies the waters when it comes to experimental treatments, ie Karen thinks a dewormer helped or even cured her son's autism because her son was never autistic in the first place just misdiagnosed