@azonenberg I'd agree embedded Linux is much harder in most cases, especially dealing with firmware updates to end users.
Tools like buildroot can make embedded Linux less painful. Run from a smallish ramdisk for ease of update.
I think some of the attraction is familiar software libraries and APIs. Using something like QT for the GUI can be a big deciding factor.
SOC FPGAs are nice in being able to share DDR between the CPU and FPGA but of course you can run that bare metal if desired.