I used to be a vehement advocate of fader scrolling but after messing up quite a few mixes I have to agree with this FR. As you can see from the following animated screen capture, the Mixer is a scrolling minefield:

Users may be more inclined to use the mixer scrollbar if it were a bit thicker like it used to in Studio One v2, as I suggested previously (FR: Thicker scroll bars like in v2).
Having said that, there are situations where the mouse wheel still has its place:
- Knobs: When turning a knob, if you release the mouse button the pointer is no longer over the knob and you need to drag the mouse back onto the knob if you need to do further adjustments, This is more noticeable on small knobs. This doesn't happen with linear controls such as faders because the fader cap is always under the mouse pointer. AFAIK only the stock plugins have knobs, I can't see any knobs in the mixer or anywhere else.
- The microphone and the mouse are in the same room while recording: A mouse wheel allows you to adjust levels silently, whereas the mouse button "click" sound would be picked up and recorded.
So I think getting rid of it completely would not be wise. I would add a couple of options as follows to selectively disable scrolling of controls only on scrollable panels, which at the time of writing is just the Mixer and the track headers panel in the Arrange View:

The same option would also be available form the Mixer's spanner menu. The two could be linked or independent. IMO if you disable it in one place you usually would want it disabled in the other too. I think it's better to put this option in the spanner menu than in the Options window where it would take more clicks to get to it, and as I said there are times where you need to be able to scroll those faders.
When the option is unchecked, scrolling anywhere on the mixer scrolls the entire mixer panel.
Current there exist the following design inconsistencies:
- Mixer faders respond to scrolling but track header faders don't respond to scrolling. Mixer color pickers also respond to scrolling, while track header color pickers don't. Etc.
- Some list controls respond to scrolling but list controls in the mixer and track headers do not. If this FR was implemented, all list controls would respond to scrolling. Additionally, list controls in the mixer and track headers would selectively ignore scrolling as specified by the option in my above mock-up, thus keeping things consistent with the rest of the application. The following screen capture shows an example of list controls in the inspector (which react to scrolling) and list controls in the mixer (which don't react to scrolling):

It would be nice to see more options for the mouse and modifier keys similar like in REAPER which allows full mouse configuration.