I would definitely agree that you need carbs to bulk. Fact is you need calories and without carbs you would really struggle to eat enough. Cutting is a different matter.

You obviously need enough protein as well.

Depending on whether or not you gain easily (get fat easily) or not or whether you want to stick to an ultra healthy diet or not you can probably get away with eating fast digesting simple carbs. If you gain fat too quick cut back on the simple carbs and concentrate of more complex slow digesting carbs.

Only you will know how your body reacts to simple carbs and only you can adjust your diet accordingly. Obviously fast digesting (simple) carbs will help you pack in more calories, but you won't want to do that at the expense of just getting fatter.

Protein is necessary for building muscle but it's also very satiating and eating excessive amounts will just fill you up and make it even harder to eat more food. Fat has a similar effect.