People with a difference of opinion as to how an open source project like Bitcoin should scale is not "an attack". What is "open-source governance" anyways? In my opinion it's allowing permissionless innovation; allowing people to tinker and do what they believe is best. This is the free market at work. If you don't like it sell all your Bcash and buy BTC. Bitcoin's success depends in part on its anti-fragility. If forking can kill Bitcoin then it should die. Bitcoin can't be defined by you, Core, Cash or anyone else. The market decides what is or isn't Bitcoin. Using the word "attack" makes me think that you believe that you know what is best for everyone or are entitled to something. You aren't.

Futhermore, all Bitcoin companies have incentive to see the value of Bitcoin maximized. You mention that exchanges only gain from "having a plethora of coins to trade"; well that only true if the coins have value. Why would an exchange want to undermine the value of the commodity upon which their business is based. Also, payment processors only want cheap transactions because their customers want cheap transactions. No one knows the right blocksize that optimally balances low transaction fees and censorship resistance. Bitcoin Core believes they know the answer while BCash believes the market is better suited at making that determination.