Final answer:
The children likely did not wear traditional kimonos due to cost, dress code requirements, or a want for modernity. Traditional kimonos are expensive and events may require simple and uniform attire to create equality and purity.
Step-by-step explanation:
The children did not wear traditional kimonos during their first recital for specific reasons related to the context of the recital and the rules governing the attire. Traditional kimonos, especially those used in kabuki, are characterized by their intricate designs, made with expensive silks and fabrics. The regulations around clothing during certain events may require participants to adhere to a dress code meant to promote equality and minimize distractions, as was the case with the Mysteries, where women and girls had to wear plain white clothing and were not permitted to wear anything that would make them look extravagant, including makeup or gold. Without specific information about the recital, options like the cost of the kimonos, a desire to wear modern clothing, or a requirement to wear dance costumes could all be plausible. However, from the details provided, it seems there might be rules or traditions in place, similar to those observed during historical festivals, where specific clothing is mandated to maintain a pure and equal atmosphere among participants.