Isaiah 23:12 The Lord, the LORD Almighty, called you on that day to weep and to wail, to tear out your hair and put on sackcloth. 13 But see, there is joy and revelry, slaughtering of cattle and killing of sheep, eating of meat and drinking of wine! "Let us eat and drink," you say, "for tomorrow we die!"
They just didn't get it. God was about to destroy many of them and send many away and they didn't believe. They had an opportunity to repent and possibly find grace, but instead they laughed.
There is a time to be serious. I like to play (especially sports) as much as the next guy, but sometimes I wonder if we spend too much time eating and drinking and not enough time weeping and wailing for the hurting and Christless all around us. God give us grace to be serious when we need to be and to celebrate and play when it is time.