its just an unregulated way of raising capital for new projects. If the project has a valid use and the coins are vital part of the project then the coin should increase in value by way of demand. Some platforms are useful but the coins are not vital to the eco sytem so might not be worth much long term. i.e Ripple is a popular platform but the currency is not vital to its use. The price of many coins is generated by speculative value only and therefore quite volatile.