Nobody is "destroying" your game. Worst case scenario is just a reduction on the number your paying supporters - less cash for you.
But again, I don't think your supporters are paying for the early release - in other words for the "privilege" of being the alpha testers of your.. ok, let's call this, game - I think they simply like your work and want to see the end of the story. In this case, your income will remain consistent as long as you provide them with regular updates and the whatever else you promised them in terms of content.
I am not to getting a side in this, content leaking story, in fact I don't care at all about that, it's your dramatic attitude that made me replying to your post.