If hitting a low E produced only a sine wave at 41 Hz and the sidechain filter perfectly removed all signal below, say, 50 Hz, your statement would, indeed, be true. However, that is far from a real bass signal. Any meaningful, real bass signal (like the output of your bass) contains significant energy above the root. And that energy will cause the compressor to reduce the gain across the spectrum. The Cali76CB does not reduce the gain of a 100 Hz signal while not, at the same time, reduce the gain of a 20 Hz signal. It's not a multiband compressor.