Why were the meetings of the Athenians long and the Spartans not?

Unlike the popular assembly (ecclesia) in Athens, in which all the adult male population with the right of citizenship took part and all important issues of the life of the policy were discussed jointly and actively, in Sparta the national assembly (apella) had a smaller number of participants (male citizens aged from 30 years) and accepted or rejected only the proposed decisions of the Archaget (later the Ephors) without discussion by a simple vote and an approximate vote count.