Anyway, what are you going to be making music with before 10pm? Surely whatever speakers/amplifier/TV you're using for your sound has a headphones output on it? That's where you want to be plugging in your headphones, not adding extra parts to a motherboard to convert line-level audio to headphones output that most people don't want. I know everyone's different, but I've never wanted to plug headphones into any computer or console since I've always used a proper amp for sound output.
At the end of the day, adding all these extra, cheap parts that everyone's asking for will all add up and make the board far more expensive for the end user. It's not just the cost of parts - there's extra assembly, design time, simulation and testing involved, all of which adds to the final price.