If Metallica sold out so did slayer?

What really annoys me is how people say Metallica sold out and saying that slayer stayed true to thrash. metallica slowed their sound down on the black album, slayer did the same thing on south of heaven and seasons in the abyss. it seems to me that the only reason metallica gets insulted for "selling out" with the black album is because it sold well. also I'm a fan of both bands so dont call me a fanboy. i just want to hear what some of you guys think. do you think that if metallica slowing their sound down on the black album makes them sell outs than slayer doing the same thing also makes them sell outs?