A single mediocre hire in the first five will often in fact kill a startup.
Great execution towards a terrible idea will get you nowhere.
Starting a business is like riding a wave between life and death. If you can hang on long enough, you're bound to succeed
You can't be focussed without really great communication
... fire fast when it's not working. It's better for the company, it's also better for the employee.
So if you want a culture where people work hard, & pay attention to detail, focus on the customer, are frugal: you have to do it yourself.