Constraints in life are a source of inspiration. One of the reasons why mobile experience is so suited for task oriented interactions, is because the medium forces the designers to make tough choices. While earlier, the designers could escape making these choices by taking ‘do all of the above’ route to design decisions, the mobile medium forces the designers and product managers to really consider what exactly they are enabling their users to accomplish. What is really important in a mobile context and what is not?
Good design and consequently good user experience comes from forcing yourself to ask tough questions, really digging in to understand what matters and them making tough choices.