does anyone know the reason sound engineers can't apply some kind of standard volume level for music cd's?

some of mine play with my preamp's volume set around -10dB and one i got just a few weeks ago - La Cherga-Fake No More - plays at -25 dB. A very large difference...which i've always found as being stupid and totally unnecessary.

See: http://www.blu-ray.com/community/gallery.php?member=Gelli
or: Axiom Gallery