I think you should just let the market decide overtime. It will be right. Just give these new coins time and most of them will fail, people will realise that not every new coin is good and will be more picky to choose only good projects. Wrong thing would be to now do some sort of a censorship and cut-off scams or bad coins. They will die on their own. And people can only learn from their own mistakes (and unfortunately lose some money along the way).