As a venture capitalist, people often ask me why big companies have trouble innovating while small companies seem to be able to do it so easily. My answer is generally unexpected. Big companies have plenty of great ideas, but they do not innovate because they need a whole hierarchy of people to agree that a new idea is good in order to pursue it. If one smart person figures out something wrong with an idea — often to show off or to consolidate power — that’s usually enough to kill it.
This leads to a Can’t-Do Culture.
You have to wonder how many ideas are killed based solely on insufficient startup funding. Ben has a good point regarding complexity of decision making structures — the more complex the structure, the less likely an innovative product will see the light of day. But on the opposite end of the spectrum, startups often don't have the necessary funding to legitimize the most innovative products.
So while startups certainly embody "can-do" culture, the necessity of funding inhibits innovative ideas from the outset.