I agree with you and think that the mechanics were given out at the right times, if they gave you what you had at the end, right at the beginning then I believe that would have been very confusing and difficult to understand.

I never found it too bad that you couldn't use some characters at certain times. I mean, they accumulate the experience that you are getting anyway, so you just need to remember to spend it on them once you get them back in your party. It's so much better than the old FF's where say I would leave Tifa out of my team, and all the game does is increase her level every so often. 
 
I am with you on the slow rollout. Some reviewers, including Brad, seemed to feel that everything became available to you too slowly, but I really didn't have a problem with it at all. Sure, they could have unloaded everything onto you in the first couple of hours, and I probably could have lived with it, but it was just as good to have them gradually give you more and more control. Maybe I just enjoy games that move a little slower, but I thought the pacing throughout was excellent, and it never dragged thanks to the storyline and interesting characters, and the battle system even in its initial form is enjoyable enough that it keeps you engaged until the next layer of it is revealed. 
 
But then again I don't get A LOT of common criticisms of this game, for me it's the best Final Fantasy since 10, and easily one of my favorites of the entire series.

I didn't like that I couldn't control who was on my Battle Team when I had more than 3 characters at once, which went on for a good 3 chapters.  They had no reason to not give me control when I was in a situation like that.

Man let me tell you about the other possibility aka Resonance of Fate. Holy shit that game just chucks you into a reasonably complex battle system with nothing. All the tutorials are optional and even then they aren't great. Even though i'm liking the game, I much prefer the way FF13 did things. 

" @Tebbit: I'm with you on those points especially with unused characters still earning CP, I remember being around 9 years old when playing FF8 and when the time came to use an all female party they were vastly underleved ( as a result of me not wanting to play as girls which is pretty immature even for a 9 year old) and as such 13 made a big improvement. I would have like to switch party members during battle as you could in FF10 though. "

It just feels like your topic is a bit vague. What exactly do you mean by "battle mechanics"? Because on the technical side all actual mechanics in battle are available after the first half an hour (minus summons) it just constantly builds by unlocking new things for you to do. And that is a classic game design choice. Look at Zelda, you get the combat mechanics from the start but as you progress through the game your options for killing dudes and solving puzzles increase. Or a game like Mass Effect where you are shooting dudes from the start but skills are unlocked as you go via the skill trees. FF13 is no different from that.  
 
If you just mean general game mechanics (like not upgrading weapons till chapter 4 or whenever) then yeah some things are slow but there are story purposes for 90% of the stuff people say is rolled out slowly, and I wouldn't have it any other way personally. Being able to customize your battle team in chapters before 10 just didn't make sense, there was no reason for it, as an example.

I think they were rolled out too slow. Not saying having everything within the first few hours would be wise (and as someone said the story dictates when certain things are introduced), but considering the way the game plays out - with battling the only real deviation from story progressing segments - parts of the early game were very boring for me. As for the party limitations on switching, it sounds like a drag, but it didn't bother me too much. The only time I really bothered to switch party members and come up with specific paradigms were all for late-game enemies and bosses where the restriction was already lifted.

The problem isn't so much with the mechanics getting introduced, it gets that out of the way within the first 5 or 6 hours.  The issue is that after that you spend FOREVER with non-complicated battle after non-complicated battle.  The changing of which characters you have seems to be an attempt at making you switch up your strategies, but the fights themselves never feel like they're getting difficult during that part.  It basically turns into COM/RAV/RAV or COM/RAV and then switch to a medic for waaaaay too long.
 
The battle system is dealt out fine, but it takes too long for the game to make you feel like you're not having your hand held.
 
I hope that makes sense! :(

HELL YES
 
Its the reason I quit this game.
 
Jesus christ, Square Enix your audience isn't comprised solely of the mentally ill.