Except bitcoin, almost coins are shit coins. They don't have uses except trading of exchange. However there is also few potential coins with good developer team and they are try continuously to improve uses. Exchange listing shit coins just because of fee, they need money, nevermind if its shitcoin. Because exchange has no loss for listing shit coin, traders will loser. That's why shit exchange list shit coins. Some reputed exchange like Binance doesn't list easily and their fees quite high. That's the reason why shit coins won't list on well reputed exchange (due to high listing fees and weak developers team). Just ignore shit exchanges so you will able to skip shit coins as well.