Performance is a two way process. You are only performing if you have an audience, and I'd argue that both the performer and the listener should be enjoying the experience. Inexperienced performers are often singing/playing well known material, so the way it's presented can actually be of more interest to the audience than the material itself.
I can't comment on singarounds because they have a different ethos and, as a non-performer, I don't really enjoy them for the above reason.