Some visit first to see if there is a social fit before evaluating the academic fit. Others wait until they are accepted and then compare the academic pros and cons of schools. Everyone has to start somewhere and some start with the visit while others start with online research. I wouldn’t hold it against someone who was in town and visited a school early in the process and hadn’t thoroughly researched their department or area of study before touring.
I think this is important.
Professors come and go and, as a result, courses offered will change.