Properties - Linear vs. Smooth animation

Wondering if anyone knows what the rhyme or reason is for certain properties using a linear interpolation while others use a bezier (ease in/out) interpolation. Standard properties listed below.

User definable:

Position (in Canvas with Transform)

Opacity (in Video Animation)

Linear:

Scale

Rotate

Crop

360 Field of View (Normal Mapping)

Ease Both:

Position (default)

Anchor

Tilt

Distort

360 Orientation (X,Y,Z)

360 Field of View (Tiny Planet Mapping)

I'm not expecting curves level of control out of FCPX (we do get it with Opacity and to a lesser degree Position) but it seems unusual to me to mix the default (and not switchable) behaviour of animation for different properties.

What really prompted me write this was my discovery that with Tiny Planet Mapping for 360, the Field of View animation eases in and out, while with Normal Mapping, it's linear. This seems very odd.

It goes without saying that as you mix a scale or rotate animation with a position animation, having different interpolations produces horrible results.

I always feel like I'm missing something obvious but I can't find any documentation on this. I have workarounds but I really wish there was a simple toggle for all properties.