The UI of your app is the one highly visible point where 99,999% of the interaction with your customers takes place. If you can't be bothered to have a good UI,

The UI of your app is the one highly visible point where 99,999% of the interaction with your customers takes place. If you can't be bothered to have a good UI, how shit is the stuff I can't see as a user ? A bad UI is a huge smell. In my experience there is a 1:1 relationship between the quality of the UI and the quality of the software as a whole.