you will be happy to hear that 90% of the companies we fund still get mocked on HN and elsewhere for "being small".
certainly agree that's usually the way to get huge. and even the "hyper-ambitious" companies we fund have to start with going after a very small market--in fact, their first products mostly sound like toys, and that's a feature not a bug.
it's a mistake to build a startup that looks like a huge government project. it's also a mistake to not think about how to be a huge company one day. in fact, i remember one of the first meetings i ever had with airbnb. i told them how i thought that this silly-seeming thing they were doing could one day change the way most people travel. i think it seemed crazy even to them at the time.