Mike Mignola... Excellent artist. Very stylized, but can capture truly kinetic energy with a few, crisp lines. Illustrator of one of the best Darkseids. I agree with Chain Lightning's analysis... Most people don't care for Mignola because his style is not "realistic" enough. A lot of these same folks also didn't care for the style Frank Miller employed in Batman: The Dark Knight Returns. The irony is that both Miller and Mignola can illustrate in a "realistic," "comic-book" fashion if they so desired (rememeber the first Wolverine miniseries?). It's like Picasso. A lot of people detest cubism because it shatters their ideas regarding art, but Picasso was an exceptionally capable "realist" artist as well.
As for the comparison between Batman: The Animated Series and subsequent shows with the same influence, that material is far closer to Mignola than to Jim Lee/George Perez/etc. or other more popular artists out there... And certainly a far cry from the super crisp lines of Brian Bolland. I suppose one could say that The Batman is closer to Jim Lee than even to Bolland, although I think the anime influence of this more recent show is telling.
I have no problem with the animation in either case. For me, it's the quality and consistency of the story and the characterizations. So far, this latest show is low in both areas and the only reason I watch it on occasion is to see the latest interpretation.