Off course they do. They make (some/many) users feel uneasy while using it. Humans love to use things that look pretty and feel "right". A well designed UI als

Off course they do. They make (some/many) users feel uneasy while using it. Humans love to use things that look pretty and feel "right". A well designed UI also makes it easier to understand the UI, what belongs together, where one area ends and another area starts.