People don't mention homebrew because it's a waste of time, and contrary to what most people want. People don't want to work on things that have an effective audience of 0.
There is no real homebrew scene. It's all people who broke their consoles, porting over other people's code bases (quake 2 on my xbox!? Who cares?!?!"), or writing tic tac toe games you can download, burn and run. They aren't worth the cost of the disc! There are no real tools, no real support, and it doesn't get anyone any closer to their original goal of making a proper game.
i would beg to differ.
The PSP homebrew scene was intensely huge not more than a few years ago(and for legitimate homebrew, not for iso loading). the psp is just one homebrew scene to exist, their still exists popularity for older consoles as well. hell i know someone who still makes full games and prints them as cartridges for the coleco vision.
Homebrew can be a huge driving force for a device(the psp alone can attribute tons of features that first appeared through homebrew), to discount it so readily is a tell that you've never been apart of such scenes,