BitMains' Jihan Wu can have a big influence on the price of Bitcoin and altcoins. By refusing to signal segwit and thus stalling Bitcoin progress he is driving up the price of altcoins. As soon as he announces support for segwit then altcoins will tank and Bitcoin will see large gains.

Obviously he can comfortably position himself to gain significant sums of money. This is a perverse incentive to first stall and then give in – that is caused by inevitable hashpower centralization.

Nodes must have the ability to selectively neutralize a miner or these games will continue to be played – miner centralization can't be avoided so its dangers must be dealt with instead.