Because a hibachi grill is a professional kitchen, the ingredients are usually expertly sourced and probably much better than whatever you can get at a home kitchen.
These restaurants have access to prime cuts of steak and the highest-quality oils and seasonings. They are also probably very liberal with their use of flavor-enhancing additions.
Another big reason comes down to one truly transformative ingredient: monosodium glutamate (MSG). This powerful addition brings out hidden flavor layers in dishes of all kinds.