I don't know if it's helpful or not for you to hear this, but as another serial startup person, I strongly second what he's saying. And marketing is a learnable skill, not a personality trait. It can even be engineered! It's also how you acquire social capital, and a "brand".

Another way to think about it is: by writing comments like the one you wrote above, about the unfairness of it all, you're already marketing. You're just doing it badly.

I don't want to sound like I'm picking on you, because this is an incredibly prevalent handicap among smart tech people.

I appreciate you taking the time to try and be helpful. Perhaps I'm just not cut out for being a startup entrepreneur when there are easier ways for me to make a living.