Again, there are different competing systems. For whatever reasons, not all airlines have gone with the same company, and not all companies have gone with the same type of solution.

Cruise ships have no option but to use satellite, since their whole reason for being is to be out in open water.

Also, cruise ships are moving slowly, so easier to "stay focused" on a satellite. Experiments with satellite-based systems for planes proved much harder, presumably in part because the planes were flying much faster and also were subject to faster fluctuations in angle/etc from turbulence (even the low turbulence that doesn't cause the seat belt sign to go on).