I think he meant is why every site and receive bitcoin should use the requirements until 1 or 2 confirmation, so like this there are several sites that are already using zero confirmation for their users to deposit bitcoin so it does not make users wait for it even though the transaction will be confirmed and require a long time, users still get bitcoin them, for example on their account at trading site, we see a lot of full transaction lately has not been confirmed whether the attack spammers in network transactions bitcoin, so if I go to a coffee shop and buy coffee warmer by paying bitcoin then I was asked to wait 1 confirmation about 30 minutes, what do I have to wait that long to get my coffee, then what if the transaction I get first confirmation up to 2 days or I chose to use high transaction costs to get a quick first confirmation probably half the price of a cup of coffee
I just mention one that is the site whaleclub.co
I look at their site using a zero confirmation, so when I make a deposit and send bitcoin we can already see bitcoin on our account there and do the trade, I know the transaction bitcoin I would soon be confirmed within a few tens of minutes or a maximum of two days, but what as our users have to wait for the trade on their website until bitcoin transactions we get one or two confirmation while we still trade in their sites.