You can make good profits from altcoins only if you choose the right coin at the right time or else its an risky affair, as the life of altcoins is not too long and it can disappear at any time, and if you want to make good profits from it then you cannot afford to miss the pumps and dumps in order to make quick profits.
Choosing the right altcoin is exactly where the main problem is focused at. Nowadays altcoins are being launched in a professional way with great white papers, top notch website, somewhat decent features. These coins mostly get seen by certain people as very interesting projects, while in fact it's nothing more than another scam coin. It's a gamble where you invest your money in. You either end up making great profits, or you'll walk out with a bag full of worthless coins.
Even coins that have been in the market for years require you to have a good amount of luck. If you buy yourself into such an altcoin, then you are hoping for a pump that will bring you into the profits. Hoping that something will happen doesn't have any value. There is no way that you can get a certain indication of what the coin in question will do. It again comes to the point that it's basically a gamble. Risks are simply too high.