My Sims stop bowling because every random townie that enters the lot heads straight to them to chat. This automatically makes my Sims pause bowling while they wait for the townie or townies to slowly get to them to chat. Sometimes the townie changes their mind and which then leave my Sim standing doing nothing and often cancels bowling activity.
I recently started using the Less Intrusive Conversations mod by Turbodriver at Mod The Sims to reduce this. So far, I like this mod. It's made a noticeable difference when my Sim is involved in a conversation with another Sim or a group of Sims that they know. It also seems to work with single Sims doing something at an Art Center or Museum where I've had them paint without being interrupted. I'll have to try it with bowling.