I don't log anything, and I also don't wander around chatting. I show up, push myself hard, and then leave. But the types of workouts I do are guided, for example I did taekwondo for four years, and recently switched to doing "boot camp" workouts. I find it is much easier to exercise when an instructor is telling me what to do than if I just show up to a gym full of equipment and then have to motivate myself to do something with it. If your workouts are self guided then it makes sense to log what you are doing so you can keep yourself on track.