I only played Legaia briefly (once, on a rental), but I do remember it had a sort of "Xenogears, only not" vibe to it, which is bad because honestly, Xenogears' battle system was pretty boring anyway. It was just Final Fantasy with a coat of "action" paint (all the button presses), only without ATB and even slower paced than its FF contemporaries (VII through IX), and actively irritating once you realize the coat of paint isn't even actual
paint but just some cheap transparent gloss (the button presses are utterly pointless because there is NO timing or execution whatsoever required to make the moves go off. You can literally hit a button, then wait for thirty seconds, then hit the next button in the chain, with no consequences). It simply adds an extra step in between selecting an attack and having that attack go off, a step that doesn't challenge you in any way or add to the gameplay experience.
That's what I would say also.
If you can be successful in battle by just faffing about then that's just poorly designed combat. It's not something you can associate directly with a turn-based battle system.
Boring combat mechanics can exists on any type of game after all, and adding a time limit wouldn't fix that. It might also alienate players (like me) who don't like to feel rushed when they sit down to play a RPG game.
Definitely agree with you about that game. It got boring fast and I didn't care much for the combo system either. I rarely like the results when turn-based RPG games try to adapt action-oriented mechanics. It almost always comes across as feeling like a cheesy half-baked action game wannabe instead of anything revolutionary. But that is just my opinion.
The way I judge a turn-based battle system is pretty simple. If it makes you think it's good. If it doesn't, it's bad.
I seem to recall Legend of Dragoon having a timing component, wherein if you hit the right attack button at just the right time, it would extend your attack, though I didn't get very far in that game (the story and world didn't grab me at all).
The one time I've seen this kind of thing implemented with real success is Mario & Luigi: Superstar Saga. The original Mario RPG had bits of this with certain moves, but Saga makes it a staple gameplay mechanic, with dodging, countering, and extending attacks something you do regularly throughout most battles with properly timed button presses. The result was actually pretty fun.
Other than that, I kind of agree that adding action-y elements into a turn-based battle system usually ends up feeling like those elements were shoehorned in and don't really work very well. Excepting the rare success such as Superstar Saga, it's better to stick to what your battle system actually IS (i.e. turn-based, ATB, or what have you) and focus on making it interesting within that system. Leave the action stuff to games that go all the way with action battle systems, i.e. Star Ocean/Tales or Secret of Mana.
I also agree with you that there is nothing inherently boring or bad about any particular overall type of battle system. It really just depends on what you do with it. Certainly, tactical RPGs let you "faff about" as much as you want while deciding what to do when one of your character's turns comes up, yet I've never heard anyone say that Final Fantasy Tactics or Tactics Ogre are boring because of that. In fact, charge turn systems appeal to me for my own game ideas, because they allow for more emphasis on planning ahead. ATB is great and all, I've enjoyed many an FF game (and my favorite in the series is IV which
introduced AT

, but the nature of it takes the focus away from planning several steps ahead and trying to set up a sequence of actions that work to your advantage, and conversely puts more focus toward quickly
reacting to what the enemy just did. I've played more ATB games than CTB games, which is why I want to use the latter for my own project (because it's something different than what I'm used to), but on the whole, both systems are good and can be fun if implemented well. But I don't see CTBs being inherently less interesting simply because there is no real-time component.