Half of what made Syndicate so good is the perspective. The gameplay was BASED on what you could do with squad-based real-time combat in an isometric view. Changing it is like doing first person Mario. Imagine that...
"It was always going to be an FPS," Nintendo game director Shigeru Miyamoto tells them. "The original nub of the idea was to take that viewpoint from the original game and zoom into the Plumber's head, and play that part. A closer experience - to become one of those Plumbers."
"We're big fans of the original Mario, and we're definitely paying as much homage to it as we can - bringing across the essence of the world, the core essence of what it is to be a Plumber," he explains. "That sounds wanky but it's true - we're taking the Mushroom Kingdom and evolving it in different ways, the shells and wacky fun. On both facets of the game, the co-op and the single player, it's very key to stay true to it." He also offers this reassurance for disgruntled Nintendo fans: "I think the game speaks for itself. We've been very lucky to work with a great, original world, and create another facet of it really. I would love them to like it. You're never going to please everyone."
Absurd, and yet basically the same thing.