It's not about rolling own crypto. My understanding is that zcash is more risky due to the newer concepts involved.
This is all theoretical right now anyways. Without more support for shielded transactions, it isn't feasible to use zcash to clean Bitcoin or other cryptocurrencies. Exchange volumes of XMR-ZEC are also too small from what I can see to make stacking them useful.
That said, we are reconsidering things. We will probably add zcash as a payment method sometime this week.