Can you guarantee me that I will make money?
YOU: "Nope. I can guarantee you that if you keep on doing what you have been doing for the last five years then five years from now you will be in exactly the same financial position you are in now. Dave, we you are in my position would you guarantee anyone they would make money?"

Again, you're being honest and you're pointing out something people often fail to consider: that there is RISK in doing nothing as well. The risk that if they "do nothing", then nothing will change. The right people will not want to risk doing nothing. THOSE are the people you want to be working with!
Bob