There are reformist and pacifist leftists too (like democratic socialists, syndicalists, anarcho-pacifists), not that I agree with any of them completely.
Leftism at its simplest definition is just opposing social hierarchy (which right wing ideologies like capitalism, fascism, and monarchism promote) in favor of socialism (which can also include communism, anarchism, and syndicalism).
It’s because leftism is so broad with differing methods that many leftists hate each other. If you narrow down the definition of leftist to only your own political beliefs, then there wouldn’t be much leftists to hate.
I agree that it’s an ineffective method, but they are still considered leftists. Marx refers to them as utopian socialists.