The origin of left

Why is it that leftists and espcially also communists bear the idea of putting the monopoly of gun ownership solely into the hands of the state?
Their history is deeply linked with fight, fight against hierarchies that suppress the rights of the workers and of the poor, fight against repressive regimes that pursue them and hunt them down - and not at all times this could be done without the use of voilence.
So, doesn't it sound like chopping your own crutches away?
You're repeating the history that repressive regimes always recurred against your people. "If they got nothing for defense, then they're easy prey." Even communistic society won't be the perfect order, and it needs to stay dynamic.
Dynamic comes from people who cannot be perfect victim to repressional means of the state motivated by the personal reasons of a single governmental worker.
In order to ensure that, you need to direct the possibility of armed resistance back to your citizens - who knows who's going to be a major one day, or when there's war coming to your countryside?
You cannot afford to protect your people only through police and the army - especially not as a Communistic state.
Reminding your roots you will remember how much of a hated species still you are.