Asking a parent to attand all of your practices can be a lot to ask. You must understand that he has worked hard all day and maybe needs to unwind when he gets home. I really would not take it personally...remember that it was your choice to play this sport and hopefully not your dads. Watching your kid practice can be time consuming and boring-sorry, but it's the truth. Maybe he will agree to come to one of your practices a week, or to stay for part of some of them. Hopefully he makes it to most of your games. Have you told him how much you'd like him to watch you at practice? Also, most parents have not been trained in how to talk with their kid about their activities....parents are never perfect and you were not born into this world with a training manual. Be patient.
Google the lyrics to a one-time popular song "Cats in the Cradle" by Cat Stephens, and leave it for him to read.
Good luck, and have fun with your sport.