Plus having a pirate version is essentially advertising for them if their product is good. Many indie title success stories I think is thanks to pirates trying them out for free and then telling everyone "Wow I just played this awesome indie title that you never would have heard of because its an indie title with little to no marketing and it is really good!" which lead to people looking at it and talking about it and getting more sales. I myself have bought numerous titles that I never would have bought based on the steam shop page. This is especially true for building, survival, or physics based games, which are pumped out en-mass, but take real talent and vision to do well enough to be worth the time and money to buy and play. Just a few games off the top of my head that I own but never would have otherwise bought without first pirating and playing them include, Project Zomboid, World of Goo, Besieged, Neo Scavenger, Oxygen Not Included, Banished. And even some pretty large titles like Crusader Kings I would never have considered buying without playing it first, and now it is one of my favorite games. Factorio would be the same thing if they didn't have a old version as a demo to play.