I am pretty sure that once you are invited to campus, that whether or not you sent a thank you note after a phone interview is irrelevant.
I did not mean to suggest a direct connection between phone interview thank you notes and job search success. Instead, I wondered if your dismissal of thank you notes and/or social skills somehow translated to a more general attitude that surfaces during your campus visits. Are you consistently getting campus visits but not job offers? This is one of the biggest leaps of logic I have seen on these fora.
"And/or social skills"? Please.
What is it with the holier-than-thou-ness today?