Not actually a bad idea as long as you choose those altcoins that have a working product. I recommend ETH but if you dare to choose shitcoins/useless projects, you are making yourself near to losing your money. Research is necessary in choosing altcoins and I suggest that you choose which you think you can benefit from it. The market is flooded with altcoins and shitcoins, we should be more careful. But if I were you, I would focus more on old coins that have been listed on big exchanges.