Entrepreneurs can get very excited sometimes: "This is amazing, that is amazing, this is better, that is better". There is basically no single aspect where the product (concept) of their seed-stage startup does not completely destroy the competition with their existing solutions that somehow served the market for the past decade. Also, commercialisation is all but in the bag after we sign that one big corporate strategic partner next month. Even the smallest of questions / challenges by potential investors are met with a relentless pounding of counter arguments even before she finished making her point.
Investors like enthusiasm, but also value realism when it comes to taking an individual on board that will have to return part of not all, of their funds to their own investors. When it sounds too good to be true, there is probably something hiding somewhere. Venture investors take calculated risks. If your company is a 100% sure huge success, valuations would be sky high, but investor returns the same as government bonds.