Hi!
By remove all shorts at the moment it means to remove them from where they are not needed, and just serve as a distraction, like the Youtube home Page, the trendings page, and when you are watching a video. Perhaps this wasn't fully clear, and I'll make sure to adjust that in the future.
In the next version of the extension that will be releasing in 1/2 days, you will be able to open a config panel to save your options as you like, and a mode that completely disable them will be added.

Thank you for your feedback :)