In the end, it all boils down to taste and appropriateness. Whether you choose to play the guitar in a complex or simple manner will depend on what you're trying to achieve and how you want to put it across. If I'm performing a song - say, a music hall number with witty and amusing words - the guitar work takes a definite back seat. Just enough to fill in the harmonic progression of the tune - and no more. If I'm doing something in which a guitar break is appropriate, i.e. where it allows a reflective pause between verses, then slightly more complex guitar work can come out - to subside when the vocal starts up again. And, sometimes, it's nice to think "f*ck it - I'm going to crank it up and have a bit of a thrash!"

It's all part of trying to entertain and, if there wasn't some egocentricity within us, we wouldn't be entertainers - would we?