What drives me nuts is if I slam my cursor against the right side of the window with the intent to click and drag the scroll bar of a maximized window up and down then the 1px wide window border gets selected and the whole window moves up and down. This has been a bug for several years.
When I select there, if I pull away from the window it resizes and won't drag. If I move the pointer up-down on the right or left side, it moves the window and won't resize.
Which seems like a sensible and convenient choice to me.
Maybe it isn't working so predictably for you?
It's definitely neither sensible nor convenient. I expect it to trigger the scrollbar, not move the whole window. The only way one should be able to move the window is to drag the title bar. There's no reason clicking and dragging the 1px window border should ever move the whole window. Every Linux window manager, Windows, and IIRC Mac System <= 9 behaves this way.