Wizards of the Coast has extensive style guides for matching look and content.
They have made a uniform push for quality and style in their artists as well.
There is a current style fad among illustrators because, art directors and _FANS_
have had a huge response to the more realistic concept art for film and video games.
As for digital, it's cheaper, easier, and cleaner. There are many traditional artists still,
but taking photos of paintings for print is a pain in the ass.
I too prefer wild styles and interesting variety.
But, you are viewing first hand the homogeneous results of non-specialist popular opinion,
and the lack of public reward for risk taking.
It's pretty much the same dilemma of every tributary of the entertainment industry.