No one can, in my whole opinion, create anything worthwhile in this insecure stage of self-doubt.
I have to strongly disagree with this on two levels: the idea that nothing worthwhile can be created while insecure, and the idea that the only worthwhile things deserve to be created.
What really determines what is worthwhile, here? Something considered high-quality by others, is my assumption of what you mean. I don’t think how well someone writes is inherently linked to their self-esteem. Very good writers can have terrible self-esteem, and still write well. Nobody writes excellently under emotional duress, sure, but that’s not the only thing that controls someone’s ability or skill. They’ll likely have a lot of reservations about sharing their work, or be harsher on themselves about it, but lacking self-esteem won’t necessarily ruin their skills.
Writing is a process of refining. Writers write a lot of things, then choose the things that they think can be worked on and turned into a final product. I’m personally a big fan of iterative design, and I frequently go back to my old completed interactive fiction projects and redo them again to make them better. The first draft will not be amazing unless you’re one of a few very limited number of people. That doesn’t mean that the bad drafts that were created were pointless or worthless. Without those starting points, there isn’t anything to work off of. Nothing can be created.
I’m also somewhat confused by your responses because a lot of what I said in the essay is encouragement for people to work on themselves. Some of this is about things that will also apply to getting better at writing, but the overall purpose of this is offering ways to change someone’s mindset toward their works in a healthier direction.
And as Snom said before me, working on yourself can and does include creating things. To decide that anything created while working on yourself can’t possibly be worth anything is the exact mindset that needs to be broken down.