That is if you are charging the fees in the same coin and not Bitcoin, if you are trading in a pair other than Bitcoin, it could make sense, when you buy 100 Xcoin, you should get 100 Xcoin, fee should be deducted from the Bitcoin amount that you have and you should see how much it is.
But that's how binance works. When buying, the fee is deducted in the coin you are buying. While in selling, the fee is deducted to coin you are receiving wether btc & eth (or maybe bnb and usdt). This is as per experience trading altcoins with btc & eth in binance.
What OP has experienced, when you are trying to sell all of your coins for a price, if there is not enough buy order for that amount and price, your order will return with some change.
That change is because of this trading rule
https://support.binance.com/hc/en-us/articles/115000594711-Trading-Rule (credits to odin81982) and not because there is not enough buy order. So to counter those dusts, I've made that suggestion. I know it will not directly help those who are selling their coins one-time but somehow will help those traders.
And for treating this issue as cheating, I can't agree with it.
Do you want to trade all of your balance without leaving dusts on your exchange account? they have a coin and if you are using that coin, you could pay the fees in all trades with that coin. what else you can do if you don't like that? you can try other exchanges.
Do you want to rank up here and participate in signature campaigns? I have 70 sMerits to sell, $200 per sMerit (why so expensive? a man has got to eat right? a man needs to have a place of his own when trying to jump a paid prostitute right? I need to achieve my goals whether by selling my activity tokens or sMerits, both are the same thing with a difference in the latter, you could earn money if you buy sMerits, buying activity tokens will result in a total scam).Binance is a top exchnage and they have their own fees and rules, so I don't see any cheating here. When you register you agree with all the rules, so where do you see cheating? Some exchanges have even more restricted rules, like Bitfinex, where you have to deposit $10k or equivalent to start trading.
Binance is not a fiat exchange. do you really need to deposit $10K in Bitcoin to trade $500? you could use another exchange if you don't like Bitfinex, but if you are a trader with Millions in trading volume, if you want to use their daily trading volume, you would have nothing to lose.