These pages suck, so here's a summary:
If you have some source code, and the source code uses the GPL as its license, then you can only share your modified version of the program if you also share the source code too.
I normally hate the GPL, but emulators are a good use for it, because emulators are heavily research-based, and everyone benefits from being able to see updates that improve accuracy.
Edit: Basically, this isn't a big deal, it's just a bunch of people shouting. All you need to do is share your source code when you share your program. This is an nes emulator we're talking about, there's not much to gain from keeping the source code secret.
The GPL is not everyone's first choice of software license, and probably not one I would choose for any project I start. However, that's what a lot of software authors chose, and we have to respect their wishes. It's just the honourable thing to do.
zbxdragon, nobody is attacking you. I have seen some of the posts that set you off, and they're just people politely asking to see source code. There's no reason not to release it... if you are embarrassed of your code, put the ego aside. Nobody actually cares to judge you based on your code. If it's the desire to have "the best fork", put it aside... nobody really cares. What does matter though, is that you respect the wishes of the original author. There is no reason to become angry when someone asks to see the source code that accompanies your binary releases.