The overly ambitious aren't expected to succeed, and the frivolous aren't seen as amounting to anything. What they both have in common is that - when they work

The overly ambitious aren't expected to succeed, and the frivolous aren't seen as amounting to anything. What they both have in common is that - when they work - they come as surprises, and surprises means you've probably discovered something new. Middle-of-the-ground companies are more predictable in a sense, less likely to stumble upon something new, and thus less likely to have a big impact.