Because normal player can't!! get to this cheap rentals. I spent hours trying to find keyla under 30 DEC, mission impossible. While some have 30 copies of it for 5 DEC. So either there is a rent sniper in play or they hang on rentals 24/7.
This is really affecting the ranked mode's as well.
In addition, once one aquires a cheap rental he can renew for as long as he wants. Until removed from owner. And as Azi sayd, alot of lazy renters.