I can't speak for anyone else, but the only reason I ever used Origin was because the final game, in a trilogy I had become invested in, was exclusive to Origin.
After I finished ME3 and all DLC content, I only played for the multiplayer aspect. When I grew tired of that, I uninstalled the game and Origin. I currently have no plans to buy anything exclusive to EA's service again, unless they buy up another developer that is making titles that I like.
The funny thing is that I really don't care about Origin that much, but I refuse to go out of my way to help EA set up a service to compete with Steam. Everything EA touches turns to shit at some point, this is irrefutable based on their prior evidence of destroying games they have control over.