Well really you say it's a lot of coin types of altcoin or other crypto coins but that makes it different just because of the many developers who want to make their own currency. Some of them are trying to do a few things just to train or test their skills. Others want to test their technology, And some experts in crypto curency have a serious purpose by creating an innovative project that will help the less fortunate in the future even also others who just want to cheat to earn easy money. This is one of the great features of the crypto curency world. Anyone can try to create their own currency and convince many people to invest in it. If people really like it or think it is profitable and even useful, they will start investing.