yet people are complaining that it has been a bad investment
I think that is because in the long run, people tends to be used in the fast changing price of Bitcoin and that is not dumping but they are used to pumping. Since the price are changing fast, they always think that it will always be a pump and they are scared of the dump. They are complaining since they are scared of what may happen in their investment.
I can consider them as the best investments in this time because they are very volatile and they are gonna give you fast profits compared to other investments. And they have been considered as the best investment that doesn't involve a real money. And they will not be labeled like that if that is not true. Besides there are a lot of people that became a millionaire because of just buying bitcoins before when they are not that expensive. And the most famous one is the the kid that buys bitcoins before using the money that his grandmother gave to him and he is now.a millionaire