a good rogue will be finding secrets, items, and useful intel in games that allow for more kinds of soft power. They can help get your team better/more loot, and they can have means of crowd control by misdirecting and distracting enemies.
Overall I love rogues, thief types especially, but I recognize that in most game types they don't really excel. In games that are just about killing lots of monsters, rogues end up being assassins/ninjas and are usually faster but softer fighters.