That, and the fact that, 'Life-or-Death' situation or not, nobody goes into a battle thinking they're going to die. It's called 'dudebro' for morality reasons. If anything, the animations are to make the team better functioning, like a well-oiled machine. Maybe the old "Dudebro" was a LITTLE bit too much, so they reduced it. Problem Solved.
No need to hate the multiplayer because of some adult motivation. Yeah, some different animations, FarCry 3 style, and even some rares, are needed, but the animations are pretty okay, in my opinion.
On the Canon side, the augmentations and training were meant to "shut up" the spartan-II's. They had to be reduced because people DID die from the changes. The Spartan-IV's are highly publicized and even Dr. Halsey is against these spartans' attitudes in Halo: Spartan Ops. Changes had to be made and they were done.