>how is it justifiable to pray the hail Mary so much while praying so much less directly to christ or the father?
Well there's a hundred different ways to pray, and the rosary is just one. For many people it might be the most time consuming prayer they do, but the purpose of it is to meditate on the mysteries not necessarily to hyper focus on Mary alone, and most of the mysteries are related to Jesus. If it's any consolation the entire first half of the Hail Mary prayer is pulled from the first chapter of Luke, and the second half is a petition for help. The prayer is not meant to just be a Marian circlejerk, it's just a very long winded way of saying, "Mary, pray for us".