Phone Calls Marked Private

Why do people make phone calls private? Does anyone ever answer a call that is marked private? It's ridiculous. I owe no one money except the USA (VA for last round of meds) and they always identify when calling. Come to think of it they only call if an appointment is rescheduled. Their collection department bills you then threatens a US Treasury investigation if you don't pay in a timely fashion. Yes, I was irresponsible and found out the hard way. You can bet they got money the next day from me that one time though, lol. I absolutely will not answer a call marked private. I have put my number on the "no call" list, but I bet it's telemarketers. They have nothing I'd purchase.

Bottom line - if you don't want me to know who is calling then you have no business talking to me. Opinions?

"Well, if I called the wrong number, why did you answer the phone?"
~James Thurber