Because it's part of a fake narrative aided by hostile foreign countries. The story about how they got it has more holes than swiss cheese. The people pushing it like Giuliani have already been discredited and literally had a Russian agent on his podcast. Maybe you could explain to me what's stopping anyone from claiming a harddrive was Hunter Bidens and creating a bunch of fake emails? We have no way of verifying the authenticity and the people bringing it forward have less than zero credibility. That's what makes it propoganda.