Lots of college students make matriculation decisions without visiting, because of various impediments to visiting (e.g. cost, time off school/work for travel, etc.).
In addition, the value of a visit is often compromised by random factors (like the weather that day, chance encounters with students who may leave an unusually good or bad impression, or how slick the college’s sales and marketing is to prospective students), so that a student doing visits needs to do some homework first to (a) compare each college based on criteria findable without visiting and (b) determine what to look for at each college visit.