AUTHOR here, folks. If you have any questions that you're too lazy to email - I'll be checking on this thread for the next couple of hours.
The page didn't achieve conveying this clearly to me. I might be a bit obtuse today but as I went on and on reading, the question remained about why exactly this tool is not just starting from well known (and trusted) Docker images. The "trusted" part is important: I kind of trust that official Ubuntu images are not tampered with anything fishy.
Could you expand on this?
Best ideas aren't always the first ones in the queue. Remember, I built it for myself first and never thought I'd do a release, so there was no point to it initially.
I see that it is first and foremost a tool written for personal productivity, so congrats on deciding to release it! No doubt, improvements can be added progressively, when/if they happen. Well done.