I think that Seedcamp not seeming to focus on the product, is a symptom of them suffering from too many cooks. These cooks probably start finding roles for themselves and end up pushing startups to put together all the elements required to build a complete restaurant rather than concentrating on perfecting a single dish.
YC being directed by just a few smart, well connected people is probably better suited in it's structure to focusing on a single dish and bringing in other people only when they are really needed.