It's pretty simple.
Action games sell more copies.
I think you're absolutely right Su but I still can't understand how they chose that route soooo quickly and with so little regard for what DA:O brought to the gamers who liked it.
I mean, why bother making DA:O if you're not even gonna continue the formula into at least the very next sequel? If it changed over the course of 2-3 games it'd be more understandable, though no less disappointing. How did they expect fans to feel?
Then, as you correctly say, they pulled back a bit for DA:I but again, why bother with that either? If they didn't care enough about the DA:O crowd to begin with, why backtrack later?
My best guess is they were just greedy AND foolish. As you said, they went more action-y but they also somehow believed they could still cater to the original fans. Like the franchise was a big snowball that would just gather loyal fans with different tastes and get bigger regardless of how they changed gameplay. It was nonsense. To me, that's like releasing Dark Souls, making it a lot easier, adding quick saves, microtransactions, air combos and a fully voiced protagonist, then expecting the original fans to continue to love it in addition to the new customers you'll bring in.
Seems like it was a mess of creative direction from EA to me, like a bunch of suits who don't understand the players just trying to magically please everyone to get the big bucks without even knowing what makes them tick. Bah, rant over