Why is it difficult to design a good UI?
Good UI design is hard because it involves 2 vastly different skills: A deep understanding of the machine. People in this group worry about code first, people second. They have deep technological knowledge and skill.
What problems do UX designers solve?
UX design is pivotal in making decisions about the way product experiences come to life and in ensuring those products are serving the user needs. Successful products solve problems. That problem might be getting a user from unregistered to registered for an event.