Paul Graham makes some intelligent calls on scale with regard to size and age and freedom of companies. The article is about allowing your team to ship code, but I found the part about startups being more free most interesting. I have noticed this pattern too. Since there are no established patterns and rules in young companies, they are free to do things now that will take much longer to pass in established companies. It is no wonder that art happens in the trenches.
For good programmers, one of the best things about working for a startup is that there are few checks on releases. In true startups, there are no external checks at all. If you have an idea for a new feature in the morning, you can write it and push it to the production servers before lunch. And when you can do that, you have more ideas.