You work 60-hour weeks. Should your employees?

(Editor’s note: Answers OnStartups is a Q&A site for entrepreneurs founded and moderated by Dharmesh Shah and Jason Cohen. This semimonthly feature highlights popular discussion topics on the forum and gives a sampling of answers from site members.)
It’s easy to identify a startup’s founder — she’s the first one in the office, the last to leave and the only one not taking a paycheck.
We founders are used to the abuse. And it’s ridiculous to expect employees to take the same amount. But still, this is a startup. Isn’t it appropriate to expect more than the standard 40 hours/week from employees?
This topic came up recently on Answers OnStartups in this question from one of our members: If you have a developer who works 40 hours/week and does a good job, how can you (and should you) motivate him to work 60, as was clearly stated when he was hired?
Even among hard-working, nose-to-the-grindstone, bootstrapped entrepreneurs, most people found it despicable to expect an employee to take on such a workload. Among the thoughts:

Are you going to pay him 50 percent more for working 50 percent more hours?
You’re going to burn people out.
You won’t get that much more productivity, but you will piss people off.
In the USA it’s not clear that unpaid overtime is even legal for software developers because they are not “exempt employees” (like management).

The most common theme was what might seem the obvious one: Focus on results, not hours. While a manager may feel they’re getting more out of an employee by keeping them there for extended hours, they could be cheating themselves out of productivity.
Ask yourself what actually matters in the long run. Is it that a certain butt is in a certain chair at a certain hour or would you prefer version 1.0 gets released on time? Would you rather an employee punches a card or he writes code with minimal bugs? Do you want someone who has no life or someone who brings fresh ideas to the office?
It’s true that startups require super-human amount of output. And, yes, sometimes it’s necessary to work an extra-long week or fix a server that’s down on Sunday at 3am. Employees should be expected to create more results than the average person, perhaps even more than they would be expected to create at more established companies. Part of the joy and pain of a startup is the infinite amount of work to do and the intense environment.
But hand-in-hand with that is responsibility and pride of ownership. The founders shouldn’t be the only ones who feel personally connected to a startup.
When you mandate hours instead of simply having large expectations, you’re not just setting up incorrect incentives, you’re also insulting your employees, their loyalty and their love of you and your company.
They already want to work too hard. They already want to devote themselves to the cause. And they already feel like they own a piece of the company’s future. By converting that zeal into a shop where hours mean more than results, you’ll kill that enthusiasm quicker than any burnout can.