I don't know anyone who plays The Elder Scrolls but I could see their fanbase calling it "Scrolls" for short. If not for trademark, they could just be trying to protect SERPs:
You can clearly see that "scrolls" pulls up mostly pages about The Elder Scrolls. (You have to ignore the pages about the lawsuit.) Then again, Notch called his previous game Minecraft, which certainly makes you think of Warcraft and Starcraft. Sounds like this is just his shtick.
No one in TES's fanbase calls it "scrolls", we call it TES ("The Elder Scrolls"), because that's what Bethesda calls it, over and over and over again. Or we mention the particular games by name and leave out the series title: Daggerfall, Arena, Skyrim, etc.
That is my experience as well. I've never heard anyone refer to it as just "scrolls."
I have heard all of the things you mention, though (TES, The Elder Scrolls, Daggerfall, etc.), but never ONCE have I heard it called just "scrolls." Ever.
I played every version of The Elder Scrolls. And I never called it "Scrolls". And never saw anyone in the forums use that term to describe any of the games.
http://www.google.com/search?ie=UTF-8&q=scrolls&tbs=... (query: scrolls)
http://www.google.com/search?ie=UTF-8&q=scrolls+game&... (query: scrolls game)
You can clearly see that "scrolls" pulls up mostly pages about The Elder Scrolls. (You have to ignore the pages about the lawsuit.) Then again, Notch called his previous game Minecraft, which certainly makes you think of Warcraft and Starcraft. Sounds like this is just his shtick.