Imo it doesn't matter much whether that behaviour is caused by some recognized condition or is just their personality. Someone could have texture related issues with eating certain food and not be autistic, doesn't make them an asshole for not wanting to eat it (not to mention that almost no one likes all food). In the end we're all mainly a product of our genetics and environment, and the specifics of what people should and shouldn't be considered responsible for is a whole philosophical argument in itself.

You can criticize people for their behaviour regardless, as the other commenter said there's a difference between criticism and bullying. And I don't think "I'm autistic" is any better or worse a reason than "I just don't like it" (using that loosely here, could include the whole range of extreme responses like vomiting). Because autism here in the end is just a label saying "congrats, you have a recognized reason to not like it". There's no way to know what precisely is going on in someone elses head regardless.