Some designers try and stay away from standard convention to prove their creativity. That can lead to wonderful results, but often there is a price to pay. That price is digestibility of the content, which translates to usability.
Imagine you walk into your favorite western style restaurant. You sit down and glance around the table. Napkins, perhaps some salt and pepper shakers, and cutlery. Oh wait, it is not a fork and knife sitting there – it is a set of chopsticks! For some people that is fine, but other people may be thrown off by this if they were expecting classic western cutlery. It may be a neat twist, but what does your patron lose from your creativity?
Websites, video games, business apps and even airport signage are no different. There needs to be a balance between creativity and convention to achieve a balance between unique experience and digestible experience. The combination of the two applied to a given situation places you somewhere on the usability scale – hopefully towards the end you want to be on.