To properly diagnose, it is important to have both readings, LOW pressure side and HIGH pressure side. You said the HIGH side indicates a pressure of 140 psi which is low, but what does the LOW side indicate? If the LOW side pressure is high (above about 50 psi) then I'd say, yes, the compressor may be bad. However, if both the LOW side and HIGH side are indicating low readings, then the problem might be simply that the system needs to be charged (add refrigerant). Or, it could be that the EXPANSION VALVE is stuck closed.
So, as you can see, the LOW and HIGH side readings need to be checked at the same time. Just looking at one or the other is not ever sufficient enough for someone to diagnose an AC problem.