Maybe Marcel Werk or Alexander Ebert can change it in the ACP settings.. Not sure
Just realised I could mark this thread as unresolved, so I did... but I can't move it to the Bug forum and besides I don't know whether it's a bug or not. Redactor may be working as designed. If this is "normal," it's terrible!
The whole editor needs to be redesigned anyway, or at least like with IPS, give us the chance to design it as we want, but I'll leave that for another topic.