1. Are they bad people? No. Just misguided. I was one of them. They need to wake up to the reality of the situation however and understand what's going on though.
2. Will it stop the people who are trying to actively hurt people? No. Will it make things a LOT more difficult for them? Yes. People who are standing up against #GamerGate are being painted as targets. If you enter the tag and don't agree, a few gamergaters will appear to "educate" you on the subject. If you still don't agree, more show up. They start dogpiling on you.
Additionally, your tweets might be screencapped (with your name and twitter handle in full view) and then shared around, so that everyone in the "gamergate" network will eventually see it due to the fact that they're all following eachother, so even more people will hop in to "educate" you. Some people might not take so kindly to what you have to say.
If you're a more prominent figure and you're outspoken against #GamerGate, you better believe you'll be screencapped and you'll have a lot more than "education" waiting for you. If we remove the people who support #GamerGate, though? We remove that network of easily painted targets from the real misogynists.
If all of the people who genuinely care about ethics and journalism are gone, all of the "good people" have left, they'll no longer have the mask of "good apples" to hide behind, and all that's left will be the true core of the tag, and the driving force that's been behind it the entire time.