After decades I got tired to switch to additive selection mode (add)-whatever 2d software I use -why bothering with a simple selection (replace) in first place? Really not needed the simple mode.. Really. Beehive me. Add should be default selection mode. If you don't add, OK... Then the command add doesn't do anything by itself. Subtract is to correct mistake made with add... Intersect is rather "special" in an everyday use and - its not the main mode you are gonna using
replace is the default currently. That is what most people use so we are leaving it as the default for now. One reason we won't change this is that no other applications has "add" mode as the default. This would make krita pretty intuitive as it would work different than every other application.
My intention was to improve a common function, because *nobody* asks for it. *the standard* of all measures is Photoshop for 2d related applications, which is superstitious and disgusting. Krita needs not to bowing in front of other applications because it's more innovative and intuitive than the competition. Let's drop prehistoric features and focus on improvement not emulation. Krita should write new rule as little as those steps are.