"If Everything Is Art, Nothing Is Art"

Forgive me if I'm wrong but it seems to me that the meaning of the cards is becoming more and more loose as time goes by. Even looking at the relatively new RWS deck and meanings compared to the current day interpretations and meanings, it's seems like a card can mean whatever you want it to mean. The question then is, if a card can mean all and everything, does it really mean anything at all? If it's all totally subjective, why use cards at all?