Monero with optional privacy (frame it as optional transparency, if you prefer) is just zcash.
The reason that Monero works as a privacy coin while zcash fails is that zcash made deliberate design decisions that erode fungibility between "private" and "transparent" coins. Monero, with view-keys, is making that same decision, just without the deliberation.
Addendum: Suggestions for coins with mandatory privacy?