The truth is we can’t stop people from investing their money into altcoins because the social media is telling them the opposite thing. And we can’t be certain too if they won’t really make it big with altcoins in the future since everything in the market is uncertain. Even bitcoin that is quite profitable these days might stop from rising in the future, no one really knows. But I believe if we can convince them to do DYOR first before investing, I guess that will help them to avoid losses in the future by not investing into too good to be true altcoins.
Well, what I have learned from this thread and based on what Zaguru12 said, I will not warn anyone not to invest in altcoins, but it's good to always let them know it's very risky to do so because there are lots of shady projects that just want to scam investors, and if they wish to invest, let them know they are doing so at their own risk, and like you said, it's uncertain that they may or may not make profit in the pump of the coin they have purchased. And perhaps if they do not buy a coin they were supposed to buy because someone advised them not to, and by chance the coin gets pumped, they will blame the person who advised them not to buy the coin when they wanted to.
My only concern with newbies investing altcoins on their first start is that if the project fails, it might give them a misconception about crypto entirely, and they may pass on such misinformation to their friends, which is not good for Bitcoin to receive a bad name for crimes committed by other shitcoins.