First of all, this is just the way all people are though. Our emotional needs are just as important as our physical needs, and when we feel bottled up and repressed from every angle, that emotional tension is going to pop off.
Second, I agree with you that the Left needs to focus better on strategy. However, I (along with a lot of political science discourse on the radical flank effect and Overton window) disagree with you that more potent displays of rage are counterproductive to building an effective movement. Simply put: if you're the most extreme thing on the scene, you're out. If you can point to someone further out from you raging and say "Look at how much easier we are to stomach than THAT," you have the chance of shifting the needle a lot further a lot faster. The right embraced the Overton window explicitly for years. It's about damn time we did the same, rather than continue judging each other for activisming wrong. It all plays a role.