The idea behind having the age restriction was likely so this wouldn't turn into a dorm--while it is a civilized place to live, it definitely has a graduate dorm-like vibe to it esp. with all the Whartonites and Penn Law kids living there.[/quote]

Why would they possibly think it wouldn't turn into a dorm?
Who else would want to live there that could afford those prices? Any professional who wants to pay that kind of rent could find a lovely, huge house (with a backyard or garden) in University City, or a decent apartment anywhere in Center City. Who, other than students, would want to be THAT close to Penn for those prices?