I just wanted to ask a philosophical question.

For AVR microcontrollers there is avr-gcc which takes advantage of the huge amount of work spent in the development of GCC.

Why the micros targeted by SDCC don't have a gcc port? Why there is no pic-gcc port? Or 8051, etc? Is it a technical/architecture problem? Licenses problem?

I've always thought that there must be something blocking those gcc ports but I don't know what it is.

Thanks a lot!