It's just an aesthetic choice, because both have the same name. Both the original and the remake count as the same game - you'll notice there's only one Demon's Souls on the list.
There's a few ambiguous ones like that in the top 100 where I chose to omit information. The Persona games, Xenoblade 2, StarCraft and Super Mario 3D World come to mind. All of these had expansions or alternate versions, and their votes are included in there, but I've kept only the base game name.
I make music, check it out here on Bandcamp, Spotify, and Youtube!
my top 50 games