There is a major lack of information and advertising around Urgent Care. Very very few people know Urgent care exists. And in what form does it exist. Its different across states and cities.
Comparatively, Emergency care/Ambulances are available almost everywhere through 911 AND take most of the mind space around urgent issues.
Finally, Urgent Care centers are not equipped to handle lots of things like broken bones etc. They just refer you to an emergency center instead.