If it's released only on Steam the release dates aren't broken, e.g. half life, left 4 dead.
Manufacturing means full copies are floating around before release, then they get cracked+distributed, steam doesn't make the full game public before release, so it can't get hacked.
Afterwords, different story.
I'm assuming custom executable means that one crack would work for one exe, so you'd have to make a different crack for each user. We'll see how long it takes for a steam-only game using this to get whacked.