Coins are not meant to perform any functions beyond acting like money.
1. We also have tokens that can be sent and received and can act as a currency because they have value in them such as Pundix(ERC20 token), OmiseGO(ERC20 token),Metal(ERC20 token). As you can see, they are all based on the Ethereum blockchain, but they offer payment solutions.
2. Not all coins can act as money or payment solution like BTC, DASH or LTC. They have different roles to play e.g Some are storage based coins, others are game based coins which you can not use as a method of payment in your local restaurant that accepts cryptopayments.
3. Also, not all coins can be mined e.g Ripple
I used to sell off a lot of Shitcoins for a much more valued Ether and BTC.