Disable 2D Phsysics

Is there any way to disable this?

Did you try to go into Physics2DSettings and setting all fields there to the minimum? For example set Velocity Iterations to 1 or 0, which should make it less heavy on the system.

I can confirm that still (Unity 5.5.1p1) the profiler does show activity in physics2D in an empty project, even if the camera is not active. Not quite sure what is going on there, but I guess it won’t have a huge performance implication.