It is unknown why Capcom desperately wants mods and cheats out of their old, single-player games.
DRM, also known as digital rights management, is a tool that allows owners of a media to keep it tightly secured from cheats, mods, or straight out copying the game to another storage. This way, developers protect their creations from being infused with unwanted mods or let players cheat against other parties involved in a multiplayer match. While it sounds good on paper, DRM has its own issues too.
Mainly the stability comes to mind first, as DRM adds extra weight to the executable file, making it run slower. It also cuts modding freedom, making players not enjoy the games that they like and optimizing their playthrough with better tools or enhancements. Back in the day, DRMs used to be simple lines of passwords you would get with the game, or more sophisticated ways such as a minigame, to unlock the media. Nowadays, it’s just an extra program running in the background to check whether it’s being modified on the go.
With the emergence of DRMs, people are not happy with their inclusion in recent years as they break the core gameplay and take away the freedom from players. Some companies, like Capcom and Namco, are notorious when it comes to usage of DRM. According to SteamDB, one of the latest games to receive a DRM update was Resident Evil Revelations, which is quite odd considering the title is 12 years 12-year-old single-player game.
If it was a DRM check on Capcom’s newest title, Street Fighter 6, it would have been understandable as it is a multiplayer title, and using Cheat Engine on such a game would create havoc amongst the competitive players. But adding a DRM check on an old release that does not allow any sort of modifications is very bizarre. It is not confirmed if Capcom would be going after other titles listed on Steam, but it is most likely that they will take caution against the people who want to enjoy their games regardless.