I am not trying to tell you that your opinions are "invalid" or "worthless." You raise a good problem well known by actual, practicing Marxists about Western "Marxists" that seek to endlessly critique society without changing it. However, it would be a mistake to not learn from Socialists in the past and present who have a wealth of experience and lifetimes of analysis to draw from. Rather, my goal isn't telling you that you don't know enough to be involved, but that I think you are making a critical error in attacking Socialists based on what I believe are misconceptions and misunderstandings, and this hurts leftist movement.
I think if you made an effort to understand what these billions of Socialists believe in and are committed to, you would better understand if their ideas and systems are valid or not. I think without reading theory that you are only going to have an incomplete and partial view, and this, while not delegitimizing your opinions and views, certainly harms the integrity. Celebrating an "end to theory" was something the Socialist Revolutionaries adhered to pre-revolution in Russia, and this was proven a mistake, while the Bolsheviks' strict adherence to theory and mass worker organization proved correct.