This statement should trigger a much broader discussion than I have time for right now.
Just a few brief remarks:
I, too, find approaching people via interests rather clumsy. Outside the net, I am first interested in personality (I use this fuzzy term here on purpose) and only later try to find out via which interests someone has become that personality. Moreover, here in the fediverse it apparently leads to the fact that many create different accounts for their different interests. Which I refuse to do (until now).
Since we can't "listen to the tone of a person's voice" here, don't necessarily learn about her mannors, the personality could be sensed in a different way. It would be helpful if people would express themselves more creatively. Simply boosting things, or spreading a link, a message, etc., is not enough. At some point, #GNUsocial was called 'statusnet' - an origin of which we hopefully emancipate ourselves - or not. Style would be of importance, style of writing, style of discussing. In a sharing culture, there is no room for style any more.
I find 'personal info' sometimes helpful after all. You say that we have learned not to share it on the net. Well, I have also learned many things offline about what I shouldn't do - and do them anyway.