Still, when I'm traveling I set the expectation that I'm only sporadically available. Not that different from normal life, actually (especially outside of working hours).
My understanding is that it's actually a condition of using Starlink for commercial aviation. Every other airline that's announcing a partnership with Starlink is also providing it for free to customers.
IMO, it's a way for Starlink to put pressure on other satellite internet providers. The utilization of free wifi will be way higher than paid wifi. And the other networks - be it OneWeb, Viasat, Hughesnet, etc. don't have as much available bandwidth.
Ultimately they might get away with ripping out the whole entertainment system out of the plane altogether for another .1% increase in efficiency.