Everyone knows that startups shouldn't try to do too many things at once. Its hard enough to build one great product or go after one huge market, its virtually impossible to do two. That said, if my vision for a company is bigger than the CEO's, an investment is a total non-starter.
The best CEOs in the world are also the most ambitious. Mark Zuckerberg, Elon Musk, Larry Page, Mark Benioff and Jeff Bezos all began with simple products and straightforward features but don't think for a second that they didn't all have dreams of changing the world.
If you founded a synthetic bio company that makes glowing plants but your passion is to make the living world around us as malleable as code I want to talk with you. In fact, you might find me hard to get rid of. If you founded a synthetic bio company that makes glowing plants because you are passionate about.... glowing plants, I am probably going to pass. The company is the same, the product is the same but the vision and the prospects are completely different.
In our first conversation your job is to convince me of two things (1) you have a magical vision and (2) you have the practical restraint to get there... in good time. If all you have is practical restraint, how can you ever build a world changing company. I suggest that towards the end of an initial meeting, if we haven't touched on your grand vision yet, you need to share it. If you're worried that you might come off as unfocused preface it with something like "In our 5 year dream scenario we own all the data in industry X and can disintermediate the entire $20BN industry Y. Industry Y won't see it coming and won't be able to fight back but first we need to do XYZ and thats why we're here today."
(In case you're curious, once you do 1&2 above my job becomes convincing you that I share the magic vision and that I have the expertise to help you accomplish it.)
Dream big but be practical.