Sure while you're at it you can add to those lists:
Bands with balls/ bands without balls. I really don't why you even needed to bring up a growl vs. clean debate.
Old prognerds aren't going to care about Nuclear Blast's roster, but metalheads who like a wide variety of music and open-minded people in general will discover a lot of new bands this way. Being on NB means a lot of cross appeal potential for fans of bands like Testament, Nile, Meshuggah, and some of the other larger, high-selling bands on their roster. NB has alot of marketing tools that niche labels like Inside Out just did not possess. On top of that, they have more $$$. Diversity is what makes a great label, not elitism.