Because for at least some, a large part of what they sell is social exclusivity. Those dirty little brown (or Jewish, or Irish, or Catholic, or Italian, or German, or in Fremont, CA, white trash ...) children will be kept away from your precious little gems.
Since school, education, economic potential, etc., are so tightly tied to social status, this is hardly surprising. It's also present in other goods: I'm sure you can think of luxury cars, foods, clothes, clubs, etc., whose appeal and cache is largely their exclusivity and the fact that the great unwashed masses can't access them. No, this doesn't apply to all goods, but for a class of them, yes. (That this is also tied to price discrimination behavior on the part of producers also has something to do with this).
What is the term used for the highest ranked colleges in the US? Oh yeah: "highly selective".
Since school, education, economic potential, etc., are so tightly tied to social status, this is hardly surprising. It's also present in other goods: I'm sure you can think of luxury cars, foods, clothes, clubs, etc., whose appeal and cache is largely their exclusivity and the fact that the great unwashed masses can't access them. No, this doesn't apply to all goods, but for a class of them, yes. (That this is also tied to price discrimination behavior on the part of producers also has something to do with this).
What is the term used for the highest ranked colleges in the US? Oh yeah: "highly selective".