Good point about exchanges with Monero. (It's also on Coinbase, of the others I listed.)
The "private by default" criticism is misleading:
- While this is important in a design which mixes your transaction with a limited set of other recent transactions, in Zcash the privacy set is all of the shielded transactions ever.
- It's not a "default" technically, it's a choice of transparent and shielded, both of which are useful. "Default" is a wallet UX question. I think the latest reference wallet auto-shields things so you don't have to remember to shield what comes in from a transparent transaction.