VC Mark Suster reconfirmed how important in-between-the-lines-body-language is when pitching investors.
If I had to put a number on it I’d say 1 in 20 pitches – maybe 1 in 30 – are by an entrepreneur who comes across as truly passionate about her project. Y [...]
The other 29 pitches consistent of many smart people who “think they have an angle on making a buck” which I know is an unfair over-characterization of the situation but you can genuinely tell when somebody isn’t “all in.”  
I am not sure about the 1 in 30 ratio, but I have seen similar dynamics when clients approach me to upgrade their investor presentation. When you are a professional manager-for-hire that makes a career in big firms, your affinity with the product is usually not that super important, you manage people and deliver the goods. When you are the CEO of a startup raising its first round, it matters a lot.

If the CEO herself cannot portray the required passion for the product, maybe it is wise to include the person on the team who can. I have seen many successful combinations of a CEO who is focussed on a execution and a “product guy” obsessed with the technology, but slightly disconnected from the harsh reality of budgets and timelines. Still, if you need to rely on this combination you definitely lost some points with VCs that you need to make up for in other areas.