mouse scroll wheel zoom

Working with KDE applications on OS X, I'm often hindered by a feature I'd never noticed elsewhere: text zooming through the scroll wheel.
On Linux, this is coupled to the Ctrl modifier, but on OS X that's the Command (, Apple) key instead.

I don't have a mouse with scroll wheel, I use the 2-finger trackpad gesture for scrolling. And I never use the Command key voluntarily with that gesture, but clearly Qt cannot distinguish a view that continues to scroll through inertia from one that is being scrolled under direct control.

So the zoom can get triggered anytime a view is still scrolling and the user presses the Command key to invoke a shortcut.

That's a very annoying unexpected behaviour, made worse by the fact there doesn't seem to be a shortcut to revert to the default zoom level.

Can the feature be deactivated or the modifier key remapped on a global, system-wide level?