Why does the game have to end immediately the pillars run out? Later players in the turn order will miss out. Why not let such players play out the action on their cards before ending the game? Presumably the designers have a good reason for the official ruling, but I can't work it out!
The pillars are visible so the players can figure out when the game is about to end and plan their turns accordingly.
Not knowing if you will be able to play your card in (what looks like) the last round, adds tension as each player tries to be the first to play in that round.
For example, playing a card that gives 6 points for the Baumeister, is not scored if played after the Baumeister who ends the game, but it is scored if it is played before!