This actually makes sense and it's logical in order to avoid transaction fees etc. If we're talking about something as minor as one hour delay, then it's not too much of an issue, is it? Your question though is valid, if we had two identical casinos, you'd pick the one with instant withdrawals. Although in the real world, there will always be some differentiation between two platforms. I personally don't believe it's intentional, unless we're talking about troublesome platforms, but it's something that has to do with batching the transactions and conducting a checkup on larger transactions, along with KYC requirements.