It is not a bad idea, but you should be careful about freezing your money. Because you can not make money by being passive by putting money into altcoins or bitcoin. It is very dangerous for you.
To some extent, yes this idea is not good. You cant just preserve your money in bitcoin or any other altcoin. That means, keep on trying what is good for you. If you found trading or investing as good source of earning, try them. But dont just hold things for so long. Rate you must be doing trading at daily or short term trading just to make something good out of it.