Yes, as long as someone can perceive the risk and is willing to take the risk then they can invest. It cannot be denied that bitcoin is the safest currency and worth investing in in the long term, but we should not be too stubborn and ignore bigger opportunities. Bitcoin will no longer be able to bring x10, x100 or x1000 profits if we invest from now on. But with altcoins, this is possible and if someone is smart enough and confident in themselves, then why ignore such an opportunity when the bull season is approaching? Don't impose your thoughts on anyone.
You are not wrong, but at the same time how many people that invest in altcoins actually know what they are doing? If a person is an expert trader, without a doubt it would be a mistake to not take advantage of the opportunities they have right in front of them.
But the majority of those that invest in altcoins are not expert traders and instead they are noobs that cannot distinguish a scam from a good project, and people like that should concentrate on just finding the best coin they can and hold it for as long as they can.