Ben -you missed the easy answer -
Too many modelers simply can't make the setup operate properly.
I still have to patiently explain big arm/little arm on direct servo linkages
as soon as the terms "torque and moment arm" are mentioned- the receptors can be seen shutting down.
In my earlier life - I designed linkages , including spring balanced linkages -which can be really tricky.
Also, I did control and pressure linkages for industrial clothing manufacturing machines .
So with similar backgrounds- - some of us see no problem in doing a pull pull setup .
For others it is simply a very daunting task -to get throw, ratio and friction all in proper order.
The first clue on all of this is the goofy 4 servos doing one job setups --
the wrong tools for the job - but cheap and available and easy to do.