The golden rule is don't put too great a percent of your networth nor own a significant portion of the float in any one of these (unless you are very sure you know which one is going big).
But my beautiful tulpes ...
The problem are not the fools that loose some money, they always have and always will. Banning stuff is goverments favourite pastime and an a altcoin bubble could be a good trigger for such. Crypto will survive, that's clear, but what about a gov regulating just btc for trades in crypto.
We a far away from such bubble in altcoins since even btc isn't known yet, but a altcoinbubble would be desatrous. That's at least a real problem on altcoins, although I'd love the money I will make on it.