I produce pre-production artwork (storyboards, character design, concept design, lighting concept design, production design) and scripts as a hobby, not as a profession. It’s “doujin” or fan pre-production, in other words.
I draw art in the form of speculative animation pre-production artwork because it's fun, and I'm obsessed with the animation production process as an animation fan, artist, and would-be professional.
It's only natural I'd have a desire to draw and write my own rendition of it, regardless of whether it's "professional enough" or not. It's still a valid form of self-expression and recretational hobby, even when it's a lot of hard work that's never going to get seen. That's just how I roll. I like designing "imaginary TV shows in my head".
"Unpaid spec work" and "spec project" or "spec" is the key word here.
I used to wonder why I did "spec pre-production work" if all it was going to do was sit around on my desk, and never actually get used in TV. Now I know.
Actually, I've already got a decade's worth of experience prolifically developing and producing "spec work". I'm just really, REALLY good at working for free. 1,000s of pages worth, in terms of artwork.