Which is why some artists should not display how freely they can do/say/show/sing whatever they like in front of their audience (they usually do not have requirements for their audience like if they will be tempted/offended by stuff they're going to do). Just like Pauls advise not to eat meat that might have been sacrficed in temples, in front of others.Actually they really don't have a point. It's more of a preference. If it is temptation for them they should cut back on it or even cut it off. They should not unleash it on everyone else though... as if it is a temptation for us also. These things need to stay at personal not for everyone.
For example: suppose I would send my children to a Theocracy gig, 'knowing' what they can expect, based on what I know about Theocracy from their albums, their video's, their websites. Now suppose one of their new songs is some deathmetal song, with grunts and all, and Matt, supporting the story the song is telling, would dress up like how a demon is supposed to look. That would be some kind of shocking. So, yeah, maybe I could handle that (I wouldn't like it), but exposing my children to that kind of stuff.... Even though the intentions would be right.
Also, Christian artists should be aware of what they show on stage is everything the audience will see. They should be careful about the message they're sending. They should not leave the impression that Christian artists are just artists with a weird hobby (just the same like any other band, but with just different lyrics). It should be clear what they stand for (lyrics can do the job here, but they should be clear), or they should not say they're a Christian band. (There's a difference between a Christian band and a band with Christian members.) It's hard to precisely describe what I mean here, but I hope you get what I mean.
And here's the bunch of IMHO's I forgot to add in: IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO IMHO.