I understand having to select a party for primaries & the pros & cons of it. That is a different & even more complicated issue. I just don't understand why whi

I understand having to select a party for primaries & the pros & cons of it. That is a different & even more complicated issue. I just don't understand why which party I voted for needs to be "public" record. I don't believe that companies & the general public need to know. I've used campaign software that shows how incredibly easy it is to select a list of people & market towards those who voted one way or another in the primary.