Sorry but no, not gonna happen. It won't be called bitcoin anymore if these kind of shits really happen.
And there is no good/bad real/unreal bitcoin, they are all same tokens sha256 verified in main block or "fork" blocks. People("tough" bitcoiner kids on internet) might or might not find out who they are and they will be just fine on doing that as before.
Motive? Why would anyone lose money, an evil miner?
They are going to double spend once the hash rate drops low enough because of the negative ROI of mining.
Motive? Quick Money. You checked the bitpay 2014 report right? rich people and big company like to get USD and EUR much more than a
bitcoin dying-cheaper-coin.