Diversification is the most important factor of every successful investment. Without splitting your altcoins among different wallets and exchanges, you won't be able to save your funds, once one of them is going to be attacked by hackers.
This is nature of crypto currency, there are so many coin who are struggling in the market since long but they did not get proper recognition but some are there only for few years but still so many people know about it and they are investing into it, holding every coin or multiple coin better invest in bitcoin which is at high demand and gradually rising in price.