If altcoins have a practical daily life usage or solve a problem and can be used by the common people then there's no need to worry, just go for the idea of long-term investments for those coins and the coins which you mentioned - "Ethereum ETH, Monero XMR, FCT Factor, and DASH". These coins do have a lot of services and have solved a lot of issues for the common people or have contributed to the technology, So if a coin has a value that is it is demanded by the people and it solves an issue or makes some major work here and its demand is high then those coins are definitely a great option for long-term investments.