You know, engines for race cars are very important: they give you power and speed to win races.
But have you ever driven a car on ice? No matter how soft on the pedal you are, it seems that all that power causes a lot of troubles … so you end up spinning around🙂
That’s the same concept for race cars: if you have the most powerful engine but it is un-drivable you end up losing races maybe not being able to accelerate out of corners due to the high amount of wheelspin.
I think you have a similar effect with user interfaces of our applications: you may have the most powerful software to solve a specific problem but if your user experience sucks … your app sucks and sorry but you are going to lose: as easy as that.