I run my own business and if you need money cash really is king. We always make sure that we have free money for unexpected expenditures and that only a portion of our assets is tied up in investments.
I think that if you have quick cash on hand you are a lot more able to get through any financial surprises that may come up. Generally when you make investments so carry penalties if you cash out early. This is true even for personal investments. I know if I try and cash out a GIC or something too early that it wastes a ton of cash. It is best to always have some on hand.