The AA low price guarantee does is NOT a sham. AA keep their end of the bargain (unlike some others I have dealt with).
Student universe does not sell tickets to the general public. Only a select few have access to these prices; if you are not a student then no good.
That is why AA should not price match to Student Universe. I appreciate the fact that AA offers special fares to students only through certain student only fare channels.
If you find a lower price through a public channel like Expedia, Travelocity, Cheaptickets, Orbitz, etc then yes, AA will and should price match.