Babies on cruise night

Ok, so i go to the Thursday night cruise in with my wife, and two other couples. One couple just had a grand baby. So, now they bring it to the cruise in. Then the baby's mother shows up. Now they are all goo gooing over this baby. Feeding it, changing it's diaper, etc. My buddy from the other couple, and I hate this crap. We get up, and walk off. Are we the jerks for not wanting to be around that, or are they wrong to bring a baby to an adult event?