I understand both sides of the situation, but I believe bringing up pirating is irrelevant for this argument. To further specify, I don't think this should be considered a primary reason since the creator of the game didn't directly state it was a reason for the swap (at least in the proof you provided). On top of this, although switching to steam made it more difficult to pirate, pirating is still very possible for steam games
I don't put piracy as the primary reason for this argument, but that's one of reasons why people should understand what he's been through when the whole backlash happened a few months ago. When i came here, Nacho himself replied to me that he was disappointed because people disrespected him and demanded more stuff from him while he already gave free updates for itch.io version and he also stated that his game was stolen multiple times. Sure he made mistakes, but he deserve to feel disappointed too and no one should disrespect him that much when he already apologized and eventually gave the Steam version in here as well. No devs want their work to get pirated so it's one of valid reason if they want to try moving their games to another platform with stronger security because even if Steam games can still be pirated, it is way more difficult than just simply copying the direct files like Itch.io version.