> µCLinux [...] recommends 32 MB for a "serious product"
My point exactly. There's currently a hole between ten-cent MCUs requiring RTOS and 5$+ RPi that can run Linux. Taking out nommu from the kernel would make any 64MB "super-MCU" a non-starter.
You might be surprised how inexpensive a small Linux-capable MPU is. The Rockchip RV1103 (1x Cortex-A7 @ 1.2 GHz, 64 MB integrated DRAM) is under $3 in quantity. High-end microcontrollers are actually more expensive than low-end MPUs, e.g. STM32N6 is $15-20.
You might be surprised how inexpensive a small Linux-capable MPU is. The Rockchip RV1103 (1x Cortex-A7 @ 1.2 GHz, 64 MB integrated DRAM) is under $3 in quantity. High-end microcontrollers are actually more expensive than low-end MPUs, e.g. STM32N6 is $15-20.