Well there are no safe or sure investments so you've just got to study the markets and make your own mind up. People don't have to invest either and if people feel like they need to they're more likely to lose their money all together.
So your investment advice is to put the money under the mattress and forget about it?
Looks like his advice is don't throw your money away but doing nothing with it is better than putting it all on a risky venture. And just because the markets are down doesn't mean you shouldnt pout your money into them. Buying at a low is the perfect time. Personally I think bitcoin will be a good investment but its not going to happen over night. I'd say hold for at least 2-5 years. Depends how patient you are.