I'm just wondering why they have such fundamental base rules wrong here. Something that has also persisted for 5 major patches and a full year since EA release.

I mean.. they had to code in scroll use somehow already, and they chose to implement it against D&D rules. That leads me to believe they don't like the D&D system and are intentionally going against it or testing the waters to transform 5e towards a more classless system like DOS. (also disengage and hide as BA for everyone etc.)

They could always just come out and say "don't worry, scrolls for everyone is a remnant of the Divinity engine we just haven't gotten around to fixing yet because it's planned further down the line". But they're not going to do that because they don't share information. They have time to dress up as druids and make LARP videos, I wish they had some time to communicate as well. Because in the end we are more interested in how the game will play.