I don't see why they can't. They are putting skill back in the game. Also, they haven't improved shooting they are just using precision as the skill gap. I've not seen any talk of shooting being buffed. If things go as they look then they haven't nerfed defending, but essentially balanced or even buffed it if you are good at the game. While they may be making auto blocks and the such less frequent, defenders should mark closer to opponents around the box. Along with what I personally believe to be a minor AI defensive nerf, all it means is that you actually have to be good at defending.
If you get scored on a lot then I'm sorry but you are just bad at the game, and I'll say the same if I get scored on a lot. The nerfs and buffs they are making aren't purely to decrease or increase realism, they will make the game more skill based. Even players that are good will have to have an adjustment period, that's just how it is. I've seen loads of people saying that these sorts of changes are what they asked for, and EA themselves have said that it is from the most common feedback they receive.