To me it seems more like you have trouble dealing with anyone who attacks your arguments, but does not take a strong position on the issue itself. You can't bring yourself to back down on the "guns are bad simply because they have destructive power" point, even though it's inconsistent with the implications of your "What are cars designed for?" post. Since you're not up against a strong ideological position here, you don't have the opportunity to dodge the issue by attacking some other point. When you can't find a way to attack the opposing arguments, you start attacking the people behind them instead.

I'm still at university. I used to study maths and computer science, but after a dicey honours year I switched to political science and gender studies.