‘Wheel of Fortune’ Contestant Loses on Technicality, Viewers Blast ‘Moronic’ Rule

That rule has been in place since the show began. I remember once someone lost because they added "An" in front of the answer.

It happened again last night.

Does anyone know the reason the rule exists? The only reason I can possibly think of is to prevent someone from using "and" as a delay tactic while they figure out the last answer, but the couple of times I've seen this happen, the contestants ran through the answers and the "and" didn't cause a delay.