This is just stupid fucking rhetoric to get things for free. You aren't going to 'force' him to release his work for free. If push comes to shove, he, just like a lot of other developers that make their own miners stop making them. Then big farms who can afford to hire actual developers get easy high performance miners with no competition.
You lose, public developers lose, and private farms win. Go educate yourself before you make fucking retarded knee jerk statements. GPL licensing has absolutely no baring what so ever here. No one is going to take SP to court, no one is losing lots of money because of this (except big farms), and at the end of the day it really doesn't matter.
People use whatever rational they want to justify their actions. Only thing GPL licensing is helping in this case is megafarms and I'm guessing your two rigs don't qualify for that status.
Oh yeah, sp is a modern day robin hood who steals from the open sources and gives it to the little miner. Get your head out of the sand man. He probably sells his mods after he's bored with them on his +100 gpu farm. And no little miner with 5-10 GPUs can profit from 2-3% speed increase, so big farms always win.