I found that most of the parent washed baby's clothes together with the family's clothes is not hygiene. While, I'm personaly think of this definately is not a problem if you decided to wash the baby's clothes together with family's clothes.
But somehow, if you found that baby clothes like cloth diapers having dirt or stain. Then its better to have some liquid detergent to remove the stain eventhough that is tough and hard stain. This kind of clothes is advise to be washed apart from everything else.
I able to found this topic from Kids Health Org.