Aside from size and curricular offerings I think a couple of the reasons some families don’t consider LACs are related to geography. Many parts of the country don’t have strong LACs so in general they’re seen as weaker than RUs. Some kids live in places with few LACs and don’t want to have to go far for college.
For instance, if you do a search for top liberal arts colleges in Arizona, Utah or the Dakotas on the US News site you won’t find a single one. In places like Kansas, Montana, Oklahoma, Idaho, Nebraska, and New Mexico there’s only one. Massachusetts alone has 14. NY has 19, PA 22. New England, with half the population of Texas, has 10X the number of LACs as Texas. In parts of the country with good LACs, particularly the Northeast, most people have LACs on their radar. Whether or not kids decide they want to look at LACs they understand what they’re about. Obviously that’s not the case country-wide.