I was recently playing Aarklash Legacy or some such. That game actually makes respeccing part of the gameplay, for whenever you are out of combat you can go an completely respec your characters both active and inactive within the framework of their role. The character system is nothing special, each character has merely four skills which after a few points can turn into one of two different skills, and by the end of the game you can only have two maxed and one almost maxed, and stats are only modified by leveling up and jewelry worn, but even with such a simple character system you can completely switch the role of each character around, or how that roles operates.
Amusingly, the ability to respec your characters at will allowed for some incredibly intense battles to be designed as the encounters do not have to be so that every potential party has either a fair chance at defeating it or must get through by liberal application of savescumming. There is a particular battle in which it is literally impossible not to get murdered in two seconds flat if both your ogre tank and your goblin rogue are not built in a very precise way, and even then it requires quite a bit of skill not to get slaughtered. It also allows the game to pull some unfair stuffies which would be impossible to pull in a game without respecs, such as enemies which use a particular skill on your tank to not only completely cancel the benefit of certain builds but actually turn it against you - It´s either completely respeccing your tank or trying to force your way through the encounters through save scumming and praying, and so on.
Which is a pretty good argument for respeccing. While the game gets pretty repetitive towards the end, and while most boss battles suck balls as the combat system is designed for battles pitting four of your dudes against WTF enemy dudes, the first half of the game, and some particular battles in the second half, are the best RTwP battles EVER - Not only because they actually are entirely designed around RTwP instead of being TB in RT, but because they are not designed to allow RPing or LARPing, they are designed to, in the hardest difficulty, fuck your shit sideways hardcore and make you go through them like a puzzle. You die like a bitch, you respec, you switch your jewelry, you try again, you die like a bitch, make a few corrections, design a good plan, try again, die like a bitch, and so on.
Which is, like, the point: Allowing you to play around and explore the system, and how the system interacts with the battle mechanics, and actually requiring you to master at least part of both to get anywhere. You can try completely out there combinations of skills which require stupid amounts of coordination between characters, and then you can go back to your boring basic configuration, and then your basic configuration is slaughtered and you need to get creative again.