Most of altcoins have nothings special and people do not need those altcoins. People just need those coins products and holding these altcoins will help investors get profit base on product succee.
You are absolutely right. Most of the altcoins have nothing special and a lot of them are actually useless. But we don't know which project will be successful and which is going to be failure. We can say that most of the altcoins are useless now, but not when they were made it.
For me I need altcoin, because in altcoin you can earn more profit, yes in bitcoin you can have profit but it can be more double or tipple if you invested your money in some altcoin and that is the reason why I need altcoin in my life because I need to earn huge profit.