Assuming that they can receive and send their money quickly and conveniently with ecash, I speculate that they will never care about the difference between centralized and decentralized.
Would this not hurt bitcoin as a currency? Would this not only encourage bitcoin to be used as a speculative investment? How about mainstream adoption?
True. But isn't it how it is already? Not sure how this ecash think would hurt bitcoin as it's already the case that a lot of people don't care about bitcoin and prefer using PayPal/online banking/etc because they don't care(and might not even know the difference) between centralized and decentralized.