I guess points balance is a way for them to quickly see if someone is "invested" in their brand as they will likely stay in a Hilton brand hotel sometime in the future to use those points.

Does anyone know how far back the front desk can see your stay history? If someone has 500k points that they accumulated a few years ago but only stay at Hilton brands once or twice a year just to keep the balance from expiring, then simply looking at the past year may not be enough.