Let me put it simply ...perhaps the fault is mine for not being clear.... here goes....
Crypto going mainstream even in it's current form (non dark) = bigger profit for everyone involved in crypto right now.
Crypto with advanced anon tech not getting to go mainstream = less profit for everyone invovled in crypto right now.
I like profit as much as the next guy, but to me adoption has more important implications than profit, though I think dark achieves both of our ends.
I simply do not see dark crypto as a threat to the crypto ecosystem. I agree with you that the bitcoin foundation would compel us to submit to anal probes if it meant getting eBay to accept it, however I think that is why altcoins like dark are necessary, as the anon feature which will invariably be painted "evil" is segregated. The anon feature however is very necessary to its growth as the core principles of crypto are dependent upon it. There are literally posts on reddit by "libertarians" warning against using crypto because its a government scheme to track you. Keep in mind, the MSM is already painting Bitcoin as the criminal currency, darkcoin can draw no-worse attention.
Crypto is anti-government by breaking the fiat monopoly, so anonymity is necessary to be effective at subverting currency controls. Bitcoin is the backdoor to crypto acceptance, while darkcoin can be the crypto equivalent of a swiss bank account. And last I checked, Switzerland isn't rich just because of watches.
With Bitcoin being the "reserve currency" of crypto, darkcoin will drive its price up because it is just now one more tool that can be bought with bitcoins (because as we know there will never be fiat-> dark exchanges). Darkcoin is dependent on Bitcoin staying the way it is.