Artists that try too hard to "RAWK" live when they really shouldn't

So I just saw Brendan Benson last night for the second time and I have to wonder why he thinks his great pop tunes should sound as if they are being covered by AC/DC when he plays live. Taking artistic liberties with your music can be fun for both artist and audience; however, when well-crafted tunes are unerringly shone through a prism of leppard-style rock they can lose some of their appeal, especially when the interpretation is quite uniform.
I wonder whether BB feels he has something to prove just because he is playing in Detroit, or if he always plays his whole set like this.

On that note, what other artists try a little too hard at the risk of turning their songs into something they aren't or shouldn't be, and why does this happen?