You can only get a certain amount of Ranking Points with lower strength decks ( http://www.edgebee.com/wiki/index.php?title=Live_Play#Deck_Strength ).
During events, those restrictions are removed, but regular live play would require you to increase you deck strength to the next level. Otherwise, you currently will not gain any points nor gold/exp for fighting.
As said, during events the restrictions are removed, so you will also get gold/exp. Live Play (and other) achievements might need some changing, but that’s for another time.