who really cannot push themselves :-(
Accusations are often admissions.
You've just admitted that talking to people requires "pushing" oneself. In other words, it consumes a person's energy to do so.
Autistic people, like I am, have very limited resources available for social interaction. I met my sister for two hours today and had to sleep for three hours afterwards because two hours of conversation takes so much out of me. Why would I choose to expend my limited resources on the people who I didn't actually choose to be around when doing so will compromise both my ability to do my job and my ability to spend time with the people I do choose to be around outside of work?
Generally, the tone of your posts comes across as judgemental and loner-shaming. You're using the same kind of language that my grandmother would use about people whose shoes were unpolished. "It's a shame" and "I'm surprised [that people have differing priorities from me]". I don't think I'd like working with you.
The enormous irony is that, over a long time, the colleagues I have come to get on with, and will sometimes talk about books, music, and films with, are the ones who respect my need for peace. The ones who try to force conversations with me, I try to leave the room when they come into it.