A minimum deposit

Why is that? As a gambling site every deposit should be fine. What will happen when you deposit less?
You must never have been to a gambling site then. Or any service actually. Every site I use with an online service for accepting Bitcoin deposits has a minimum. Because every input you receive in Bitcoin makes your fee go up. Imagine if small inputs that are almost the same size as fees come in. 10 small inputs or dust can become very expensive to spend.
Well on most sites i am playing there isn't a minimum deposit amount. If i want to deposit 5k sat btc or 10 DOGE is all works fine.
Don't forget about the fee which is always there. So if you want to deposit 5k sat btc, you need to pay for at least 3k sat or more for the fee. So I think it is normal if the site has a minimum deposit amount and the minimum deposit in that site is fine for me. With 1k sat btc, I think many of us can send any amount, but as I said before, the fee will be there so it's better to deposit 100k sat btc because you can use it to gamble for many times. The fee of dogecoin is not too big depends on btc, and I agree that deposit in Dogecoin will better than bitcoin.