Previously, using a trackpad with Blender on a Macbook was surprisingly easy and natural: Two-finger scrolling would smoothly rotate the view, pinching would zoom, and scrolling through controls was smooth also.
Recently, however, I have discovered that the trackpad seems to be acting like a mouse: scrolling zooms, multi-touch gestures aren't recognized, and scrolling scrolls in increments, like it does when using an old mouse-wheel.
Nosing around in the input preferences, I found that disabling the first two
Scroll Up and
Scroll Down controls under
View2D Buttons List disables scrolling altogether, but content still moves from trackpad's inertia (without snapping to intervals, like desired). Also, disabling the last two
Zoom View controls under
3D View > 3D View (Global) does the same thing. I.e., two-finger swiping in the 3D view does nothing, but inertia from the gesture rotates the 3D view like desired.
How can I restore the old trackpad behavior? It seems like Blender is not realizing I am using a trackpad, but it is treating it like a mouse.