Of course it is so. When you are just playing with $10-$20 it is not a problem but when it is a business - you have to analyze different casinos and their prohibitions. Or it is possible to get ban with big deposit. It is possible that some casinos will be waiting until your deposit becomes big and only after that they will ban account.
Using $10-$20 to gamble is recommended, especially for new gamblers who don't have much experience playing gambling. But if the casino site has banned us by blocking our connection to their site, we should avoid it than sacrificing $10-$20 just to get blocked in our account. Even though it's a small amount, it's still not worth it because we can use the money in other casinos that won't block our account for violating their rules.