Because the assertion you make that updates are a scam is patently false. Updates, such as the one you didn't want to download, contain security and patches intended to keep your phone running. You are misinformed that updates are a scam. For example, did you know that if you did not update to 10.3.4, GPS would ultimately not work anymore on your iPhone 5? That means location services and maps would stop running. That's not a scam. That's doing something important to help your phone continue to work.
You might be better off with a flip phone as opposed to a smart phone if you prefer to avoid doing updates intended to help keep your phone working.