IMO, "scroll here" should be the default action for clicking on a scrollbar. There are already good keyboard shortcuts for page up and page down, but there cannot be a keyboard shortcut for "scroll here". It's wasting the capability of the mouse to duplicate keyboard functionality when you could be benefiting from unique mouse-only functionality.
With regards to Qt, does that mean Qt apps on Windows or something? I use KDE so there are a lot of Qt apps and they are all click-to-scroll in the scrollbar. Of course it's KDE so it's configurable so you can change it to click-for-page-up/down and middle click to scroll, but left-click to scroll is the default.
mrob · · focus · HN ↗
GTK gets this right, and Qt does not.
garciansmith · · focus · HN ↗