Why are music/ambient volume so low by default?

A big deal for me in D2 was the music, ambient sounds etc. I was kinda missing this in D3. Maybe it's because I usually don't put game volume up too high, but I was almost thinking there were very few ambient sounds (not true). All I was paying attention to was the VO and the spell/attack sounds. However, I now set the sounds settings like this: http://i.imgur.com/B5Gch.jpg

Much better for immersion IMO. The music in town, the little noises in the open areas etc. I love it.

Would be nice if they could turn up the default volume a bit for music & ambient, so people really get to notice these.