While a Lean Canvas is a great way to deconstruct your early stage idea into a more coherent business model story, your stakeholders (investors or budget gatekeepers) struggle to see what you see.
A business model story (even with some early customer validation) just doesn’t cut it for them. Before you discount this as just an investor perspective, you are the first investor in your business. While you may not invest with lots of money, you invest with your time -- which is more valuable than money.
All ideas, especially good ones, consume years of your life. Do you really want to spend the next three years of your life on an idea with a "Let's see what happens" approach? Focus on defining the destination first.
Founders, investors, advisers, all three want the same thing: help turn the idea into a "big enough" business to make it worth their while.