I'd wager the boot is cumbersome to carry in your squad car, and fiddly for the average collegiate parking attendant to figure out as far as attachment points.
As much as I like to dig, truth be told, I've been on the UT campus plenty trying to maneuver around cars whose owners just couldn't find an acceptable parking place. They just bailed out wherever. Now, undergraduate parking passes are hilariously expensive, there aren't enough parking garages, and the restrictions placed on them are just asinine. However, just stopping your car and clogging up the street for everyone else has to be dealt with.