Well, my white feathered birds have very light skin. That may have lead to the white meat rumors.
Coturnix are coturnix are coturnix! They are not IMHO dark meat birds, by any stretch of my imagination however they are not bobwhites or all white meat butterball turkey breasts in those nifty plastic wrapers.
They are what they are, and nothing more!
They have an upside, and the downside is that people that only like bobs (only like bobs). That's just my opinion. There is a cost and time factor in play all the time with live food. Coturnix have a very small time/feed factor. Bobs have another, and chickens have another.