I would say that when you've mastered the game, it no longer becomes necessary to use TGCid. He is meant to shepherd the player through the difficult stages of that point in the story, where you're being given some sticky situations to deal with.

But using him all the time is just admitting that you don't actually know what you're doing.

Still, if you're just having a good time, it's a lot of fun to mow down Treants in the Siedge Weald.