I am a bit mixed on this. Generally, I'm okay with it. But there is no disputing that a lot of other people in the community are not okay with graphic violence - it is, in effect, being forced down their throat. They see it without choosing to when it's being worn in public, and they cannot unsee it.
There is a fine line between freedom of expression and respecting other people. As metalheads, we might be outside the "norm", but that doesn't mean we need to be douchebags about it - respect should be mutual.
So in summary - I really have trouble making up my mind about this.