Before the rule change to PKs, when they just played on and on, sucked worse than PKs. There's just no perfect way to decide an elimination game/match that ends in a tie. Who wanted to watch more soccer the way they played the last 30 minutes?
People like to brag about soccer not having commercial interruptions and timeouts and such as an attraction of the sport, and it is a plus, but this is the negative consequence; gassed players barely getting any rest to the point where they're incapable of actually playing soccer to decide who advances and who has to wait four goddamn years to get another chance at the World Cup.
Edit: And even given how tired they are and how bad the play on the field is as a result, I'd still rather have that than something so arbitrary.