It is backwards if you just want the Hilbert transform, but hilbert is part of the Signal Processing Toolbox, and maybe the users of this toolbox always use a Hilbert transform this way. To quote the documentation, "The Hilbert transform is useful in calculating instantaneous attributes of a time series, especially the amplitude and frequency. The instantaneous amplitude is the amplitude of the complex Hilbert transform; the instantaneous frequency is the time rate of change of the instantaneous phase angle."
But you have a point - they could have named the function analyticsignal.
