You're arguing two different things. If Santander sucked and no one knew what the problem was, then that's different than "Anthony Santander has said that his shoulder/hip issues are helping him limit big swings", which is clearly an injury impacting a player's ability to do the only thing he does well (and why he got the contract in the first place). If all the players you listed were hurt, the org knew they were hurt, the org knew that they made adjustments to their swings to compensate for an injury, and still continued to play them to horrendous results, then yes, they would also get fairly criticized for it as well. If Tony was healthy and sucked, or it wasn't clear that he was hurt, then that's a different story.
Just put him on the IL. Maybe that doesn't solve anything but throwing him out there everyday isn't helping either, especially if he's not hitting for power. Tony not hitting for power might be one of the worst players in the league. He literally doesn't provide value in any other way.