It was probably the best system for Free Run and multiplayer, but I could see the single player's issue if you didn't want to micromanage spell casters' spell lists or use up one of your precious right stick command slots. Although now that we're starting to get a standard of having an L1 Shift for up to 16 command slots, I hope we can get a similar system in the future. It felt like the combination artes in Xillia were designed to be a more single player friendly version of FoF combinations.
Edit: When it came to learning combos, the game kind of gave it away that a combo existed whenever you learned a new arte. When looking at the arte's description, you could hit a button to look for more information, and if a page was missing then it meant the arte didn't have a combo. Alternatively, once you got that arte customizing subsystem, artes without FoF change ability had an entire customization line blocked out. Once you knew that arte could combo, then you just had to have Tear or Anise spam Light and Dark spells to quickly find out.
Oh, and I loved the fact that you could use an FoF change to link into a Mystic Arte, and the fact that you could link Normal->Arte->Arcane->FoF Change->Mystic Arte. It's been a while, but I think you could insert something extra in there too. Spell casters could also do FoF combos with other characters' spells or their own if they were fast enough without having to put themselves in danger as long as their target was in the FoF circle. And even if they weren't, in the case of something like Healing Circle, you could use manual targetting to make the FoF change happen anyway as people were retreating.
...I really liked FoFs...
....sounds like people didn't know how to set up their team mates.