Ok, well I wouldn't be turning it off anyway so it doesn't bother me at all. I wonder why they chose not to give the choice, I guess they figured the main fans who would care enough would mod it out?
I can think of a few reasons...
1. They're using finishers to sugar-coat a melee combat system which really hasn't improved all that much.
2. Finishers are tied in with perks somehow.
3. They're forcing them on people purely because they think they look super awesome, with no regard for the fact that a lot of people don't like that kind of thing at all.
My guess is a mix of all three.