here's the thing: there's absolutely no legal precedent that prevents you from modifying an executable file you legally buy, and any company that actually pursues that legal precedent would be absolutely destroyed by the pure hate of the internet crushing down upon them
I think there are some, which went in favor of modding
not entirely sure about executables, but there were some cases for old hardware with cartridges
a company reverse engineered how it worked to make their own games for the platform, was sued, and then won
I'm pretty sure it's only the music industry that manages to shut down the right of fair use
if you try to crack their encryption on legally obtained music for use on other devices, then they get pissy about it
but overall, I can only justify a company stopping any form of modding for multiplayer games, if it's negatively affecting other players (ie an aimbot/wall hack/other cheats)
but for single player games, I can't really see a company having a good argument in court
