You may be right, except ONLY those that have been proven to have the best rock-solid privacy will become the ones that rich people with $Millions will store their money. For example if you have money you wish o hide from your wife because of divorce laws in your country, you will not risk that by using a coin that "claims to have" privacy or has weak privacy and/or security (for example Dashcoin). For the majority of saving accounts which will not have much money, yeah, most people will not care and good-enough privacy is OK. So there will be different coins with different use-cases. Both may gain sizeable market cap but for different reasons - different users and use cases.