Don't worry that someone might pirate your game. If it's good enough they will. DRM should be the last thing on your mind. 

What you should be worried about (besides making a good game) is how your customers will find your game and buy it. How will you collect feedback from players and communicate news and distribute updates. 

It's possible to do all that without Steam or any other service, of course. It's just that Steam makes all that and more effortless for you. I'm not a game developer, but it seems challenging enough without writing your own distribution software. 

One copy is so insignificant that you're sure it doesn't matter.

Ethics are very different from one another. For example, I know a Bulgarian who got high morale and wouldn't exploit or steal something from anyone but he has NO problems downloading movies & games.

A few times I've asked him to get some game on Steam so we could play eachother (Hey, can you get <game x> on Steam so we can fight eachother? :)) and he always replied with: "Why should I buy something when I can just download everything from <name of Bulgarian torrentsite>?"

That line of reasoning disturbs me and has done so for many years. It tells me that he doesn't care at all about the wellbeing of the PC gaming industry whereas I care.

I did buy Galactic Civilizations II because of Brads journals about it. I wanted to reward a developer who focus on good AI. Though it must have also been that I feel more connected to Brad and Stardock than another faceless developer.

And those decisions made by individuals add up. Because if they didn't, piracy wouldn't be a big deal. So yes, I'd suggest a true understanding of the loss of justifiable revenue to companies who count upon it to make games could make a difference. At the very least it would get people who steal games to at least think about what they're doing, and whom their behavior is affecting.

And me, too. I don't see how a person of moral principles can justify stealing a game. Unless they've split their minds in half. We humans are very ingenious about working out all sorts of justifications for such things, of course.

Stardock does have more "face" than just about any mid-sized game developer I can think of, though they're not alone in pursuing this course. And I agree: it's the sense that a company has real people working in a real environment, making games, that gets around the strange idea some kiddies have that they're somehow taking part in a grand revolt against the Powers of the Universe by stealing a game. When you reduce it to the level of a person's family that gets an income from coding, a very different picture emerges.