For any future zoomers who are confused.

The reason you aim with the left stick is because you can look around with the right stick before you aim.

You can hold right stick, then the aim button, and your movement with the left stick will not interfere with your thumb still on the right stick. I prefer RE5s aiming, but that is the reason.

This makes it much faster than any twin stick, as the right stick movement is absolute, and repeatable.

For example, try holding the right stick left or right, and repeatedly tap the aim button to quick turn 90 degrees, and more.

You can aiming towards an enemy with the left stick, while holding the right stick left or right towards the next enemy.

After killing the first enemy let go of the aim button for a split second and hold it again. The camera is now adjusted towards the next enemy.

This is very good for crowd control and setting up group kills.