You spin the mouse wheel to control the scroll bar, so of course spinning the wheel towards you (down, if you align the mode with the screen), should make the scroll bar go down.

This was, for a long time, uncontroversial. However, after touch screens became widely used, people started incorrectly assuming that the mouse wheel “moves the screen” (absolutely ludicrous), and decided that down was up and up was down, and that the sane way to scroll with a mouse wheel or touch pad was “inverted” and not “sane”/“normal”.