The way to look at it, is that the "active" part of combat for melee fighters is actually the management of HP and Stamina. You can build a wide variety of "actions" from these somewhat passive skills, and the key to effective combat is using the right ones at the right time. Managing your HP and Stamina can mean the difference between being an effective tank/damage dealer, or simply throwing everything you've got at once and causing headaches for your healers - and the inevitably quick death of your group/party I doubt that's the answer you wanted to here, but I think as you get further into the game, you'll appreciate the system more. Stanzas and credits are very limited on Silan, but once you're levelling on the mainland you'll have plenty of opportunity to vary those actions, and to see exactly how each one fits into combat style and effectiveness
Ultimately, the skills themselves *are* passive, but they're used to build different techniques that you actively switch between during combat.