Using an established cryptocurrency doesn’t provide a good way for them to profit. MobileCoin is pre-mined and the majority of coins are held by founders and t

Using an established cryptocurrency doesn’t provide a good way for them to profit. MobileCoin is pre-mined and the majority of coins are held by founders and the MobileCoin organization. They want to sell you coins, so partnering with Signal to force you to buy their coins to transact on the app gives them a revenue stream. If they simply added Monero, they wouldn’t be able to sell you coins.