I sort of agree with this but my parents constantly had people over when I was a kid. That and my oldest daughter is a raging socialite at college, lead RA, secretary for the university student govt, just got invited to box seats with the university executive leadership for a football game, has 3-4 friend groups and a core couple deep friends that she meets constantly.
A little nature a little nurture, but to be clear I do agree with you that it's better to model than not.
Yes, we are in full agreement here :) The parental role model part won't override the Big Five in most cases. Parental behaviour does help in expanding the possibilty space a bit, though (e.g. an extravert can - to a certain degree - learn to relax while being alone and vice versa).
The other caveeat I conveniently ignored is that parents are usually adults, so the image they provide is for adult behaviour. Kids won't necessarily transfer that fully into their current situation. It does shape their inner image of adult behaviour, though (which starts to become more relevant as the kids enter the early teenager years).
A little nature a little nurture, but to be clear I do agree with you that it's better to model than not.