Usually until they are in their mid-to-late teens, kids on soap operas are one-dimensional characters who are brought in for the occasional "cute" scene but then are sent away for milk and cookies with the nanny. That's why characters are often SORASed; you see a character who was 6 one year and 16 the next year. So to have a sudden influx of young children on a soap opera would mean too many kids and not a lot of age-appropriate storylines. Not to mention that there are strict regulations regarding how many hours a young child actor can work, and soap operas are brutal as the actors are required to memorize many pages worth of lines in a short amount of time.