Taking on every encounter with full powers is just lazy design. It's not something a CRPG needs. It's easier for developers to balance. It also leads to massively repetitive combat and less dynamic classes. DA combat sucks because of this, and DOS took a puzzle approach, which I personally hate. The D&D resource management system is more interesting, more dynamic and more rewarding. It's really cool that classes really play and feel different. You have the more straightforward Fighters and Rogues, and then Wizards that play "smarter", having to make decisions when to use their powers and when not to. That's how you can have powerful spells in the game that feel really good to unleash. Games like DOS where casters are just different skin to do the same 50 DPS are boring.
