A scary game, after a big sale, on Halloween month, after maybe not being able to play the new one (cash, hardware requirements), yeah maybe not you, but apparently a ton of people were interested in jumping in.
When a popular game is getting a lot of attention, a game that I can't play (console exclusive, multiplayer team focused which I tend to avoid, etc.) I sometimes end up looking for similar games because of the attention. Call it a type of genra advertising. I remember when Rust was popular on twitch, I want nothing to do with public Rust, so I became interested in survival games like "The Long Dark." I used to be interested in Pokemon, then never bought a handheld after the Gameboy Brick, suddenly a Pokemon like game showed up on PC and I grabbed it right away.
I have no nostalgia for games like HL2 or L4D but every now and then something sparks my interest in returning to games like Final Fantasy XII or XI (XI big time, especially with custom servers).