Why aren't there more Designer founders?

Even though A great product experience can suck, If the design of the product doesn't any makes sense. If a user doesn't have any interesting product experience, the product will not make it so far—the design communicates visually, connecting with a user emotionally. So, I believe Designer could come up with more exciting product Ideas compare to anyone, but here we are! I am not saying there are not any designer entrepreneurs are out there; some of our most favorite websites Airbnb, Twitter, Flickr, Pinterest, Kickstarter, were co-founded by designers. But, the truth, that is not a high number, I'd say. So, What do you think is the reason? Do you feel the same opinion as I do? Or, Do you have another view as well? Please, Do Share, and Thank you for reading this!