Some of the story battles do require specific tactics, but it's true that most random battles don't. Wiegraf, for example, can't just be plowed over, nor can the battle that follows.

I tend to use tactics more often than not simply because I like to use a diverse amount of jobs. Sometimes the jobs I have selected aren't ideal for the situation so I have to use some tricks to win. Those end up being the most fun/rewarding battles (unless I lose, in which case I curse the game forever).