Gimp is basically originally a clone of Photoshop 3/4 without most of the subsequent ui improvements. I can't confirm it but I wouldn't be surprised if the flo

Gimp is basically originally a clone of Photoshop 3/4 without most of the subsequent ui improvements. I can't confirm it but I wouldn't be surprised if the floating selection thing was also Photoshop behavior at the time. So the difference isn't really how gimp started, it's just that development was mostly dead for 20 years and nobody put the work into improving the UI. Blender also used to have a bad UI but people worked really hard to change that.