So from what Antiriad said:
Programming any emulator is theft plain and simple if you charge for it in any way?
Programming an emulator and releasing it for free is the right thing to do, suppports a comunity of decent law abiding people, and should be praised?
All I can add is that the act of programming an emulator is either legal and should be done or illegal and should be stamped out, so which is it? You cant have it both ways just because money chages hands or not, thats not how the law works.