On the contrary, the minor arcana have as much meaning behind them as most of the major arcana. 

"In tarot, swords correspond to the element of Air, and as such signifies freedom but also quick change. The Swords suit also traditionally represented the military, which implies strength, power and authority, but also responsibility, violence and suffering." 

A general gist of the suit of swords. It pretty much is the same amount of detail as the rest of the major arcana are given, the Megami Tensei wiki also has more information on the arcana. Also if you narrow down, each individual card in the suit also has it's own unique meaning. When constructing my character I tried to adhere to as many of the cards as I could. There really aren't that many differences between the minor and major arcana, other than some aspects of scale that exist in actual tarot readings. That said, sword arcana have been used in both P1 and P2, so it's not like that difference has stopped Atlus.