None of these bands are anything like Manson.
No, because they can actually play music rather than screaming down a microphone. MM had his 15 minutes of fame and he's gone now.
Just maybe acquire better music taste than Nightwish and Evanescence before criticizing other people's music. Just a thought.
Does that mean I can't criticise Panic at the Disco, because I like Amy Winehouse and Bowie and Beethoven? I don't see the logic there, different isn't always bad, and clever music isn't always likeable.