The attribute called TOM is the ability to understand what thoughts another person is likely to be thinking. For this to affect your actual interactions with other people you have to be able to discern and respond to their thoughts in real time. Having an excellent ability to work out what someone might be thinking in theory or in retrospect wouldn’t help your relationships with people if you are unable to do it while you are engaging with them.
Saying that difficulty with relating to others is due to lack of theory of mind is therefore not particularly helpful, as someone can have a brilliant theoretical understanding of how minds work, but this is useless to them in practise if they don’t have access to that understanding when it matters most, that is when actually interacting with other people.
My guess is that most obstetricians are male, and have a better understanding of the processes involved in childbirth than most mothers, all of whom are female. Despite the fact that male obstetricians have the best theory of childbirth, they will be trumped every time at actually producing babies by women who may have absolutely no theory of childbirth, but possess the equipment to produce babies.
Similarly autistic people might have what would be called in everyday English theory of mind, however without the equipment to intuit what other people are thinking this theory does not enable actual real time typical social interaction.
It seems to me that a disproportionate number of autistic people study psychology, however this study being theoretical doesn’t really help them with actually getting on with people. Many non- autistic people who have never formally studied psychology have an intuitive grasp of what another person might be thinking and use that to socialise.
However, the idea that autistic people lack “Theory of Mind” is often a barrier to people believing that they or another might be autistic, because the relevant person is extraordinarily adept at explaining motivation, despite not getting along easily with other humans.
So while I do think that autistic people tend to lack the ability to intuit the thoughts of others, I know for sure that we don’t lack empathy and many of us are superb at explaining psychological theory!