Permanently disable the "All Tools" sidebar.
If "All Tools" was a living creature, I'd destroy it with Samurai inspired violence!
If you add a "disable sidebar" function to a near future build, I'll build you a state-of-the-art spaceship that's fitted with cannons that shoot armies of blood thirsty killer crocodiles @ all your enemies. The crocodiles have cybernetic eyes that shoot swarms of heat-seeking killer bees that were trained by the legendary Samurai, Miyamoto Musashi.
Discuss my "Once In A Lifetime" offer with your DEV team & report back.
AdminBhawna Arora (Admin, Adobe) commented
Thank you for your valuable feedback. We are pleased to inform that we have taken this concern into consideration and will be deploying this feature in near future.
This privilege is already supported in Acrobat and we will now be supporting the same in Reader as well.
Path in Acrobat : Hamburger > Preferences > Documents > Restore last view settings on reopening the documents.