If Bitcoin mixers are designed for criminals, privacy coins are designed for criminals only too. Why do ordinary people need privacy if they have nothing to hide?
That is a really flawed argument, privacy is a right and just because you don't have anything to hide then you don't need privacy. If I were to use that logic, that also means that people doesn't need clothes because they don't have anything to hide because clothes is some sort of privacy. Privacy coins were designed to be used by people that are living on surveillance states.