You have to remember that not everybody pirate to keep all their games in one cart (not saying that I disagree with your POV. I have a similar stance but that is beside the point). Check out the "When is piracy ok" thread and you'll see all the arguments for and against.
And I am pretty sure that nobody in their right mind would honestly try to classify this as homebrew. It's piracy through and through. No argument about it.
And oh how I hate those multi-in-1 bootleg crap of a cart. Got burnt back in the day with the GameBoy games and I never touched it ever again.