you can't stop people from copying an open source code and create their own version of it. and also this is a free market and it must remain like that which means anybody is free to create a new coin and release it to the public.

the only thing you can do is to start educating others (the newbies) so that they can understand the difference between a real project and a real coin like bitcoin and a shitcoin copy like bitcoincash. if you do that, then you automatically and eventually stop "forks shit".