From Fallen London Wiki

As many have said and will continue to say, MAGCATS was always a stupid acronym and I'm glad its obsolescence is becoming further engraved in stone as time goes on. It barely functioned as it was, because some genius decided it only needs 1 M when we have both Mithridacy and Monstrous Anatomy, just cherrypicking random capitalizations.

It's like if back in the day, we used the acronym SAIL for the highway stats, because Shadowy dAngerous, persuasIve, and watchfuL. Completely asinine.