Even though some features are similar to other readers (e.g. Adobe Reader), we don't necessarily have to implement features *exactly* the same way.

If we let the hand tool button change the state of the preference, this preference would the be the only one that the user can set from the main UI. This seems very inconsistent, and confusing, to me.
Furthermore, I think it would be an *extremely* bad idea to toggle a persistent preference when a particular keycode short-cut is used. Consider for example a user that presses the <kbd>H</kbd> key by mistake, and then don't really understand how to turn it off.

If this discussion should continue, I would suggest that it is done in a follow-up issue to the hand tool PR (once that gets merged).