i agree; communication is very complicated and for example even understandings of common phrases varies sometimes not just regionally but from person to person, so it makes sense to me that people in general often struggle to pick up on hints, especially the more subtle the hints are, and that's no one's fault. for hints in terms of sexual/romantic i think i would also probably factor in self esteem as depression and anxiety are epidemics in our society that are only getting worse as it becomes harder to maintain social lives as third places disappear. low self-esteem often comes with depression and anxiety and people who struggle with it may assume that no one would/could be interested in them or be flirting with them. idk, that at least described me for a long time when i was younger. in the case of my bf he's also autistic and struggles to pick up on social cues in general, much less flirting