One of my pet peeves when it comes to management is when someone tells me, "I'm sorry, but I don't have time to explain."
When that happens, I think that person has been watching too many action movies. If you're on the run from a secret government conspiracy, you probably don't have time to explain your actions. But the same doesn't usually apply to your upcoming marketing campaign or product release.
In the startup world, it's rare to have assembly line workers who are just supposed to do as they're told. (as a side note, the Toyota Production System has already proven that even assembly line businesses are better off with engaged workers who focus on process improvement)
We hire smart people, and give them a lot of freedom. That's one of the main reasons that startups run rings around their clumsy competitors. But the only way people will be able to contribute is if you give them the big picture.
Conveying the big picture takes explaining, which takes time. And because speed is so important, we often begrudge this time. But skipping explanations is a false economy.
Skipping explanations will put you in a death spiral of micromanagement. The less you explain, the more you will have to specify future actions. Eventually, you simply run out of time (and employees).
If you feel like you don't have time for explanations, that's probably a sign that you're unfocused. Get a few crucial things right, make sure your entire team understands those things, and rely on their judgement to get the lesser things right.