They are pure devotees who have attracted Krsna but still in their dealings Lord Krsna sees, I have come here with all the sages, my devotees who broke their rules of conduct. Usually sages of those days used to never travel on chariots rather they would walk their way. But just by getting an invitation from Krsna. (Krsna was going on His royal chariot) all the sages climbed onto the chariot breaking their rules of conduct.

So, they are great surrendered souls who broke the rules of conduct and in one way traveled in a very royal way ( in a horse driven chariot). So, Lord Krsna wants to teach Srutadeva and Bahulasva that. Yes I appreciate your love for Me and that's why I reciprocated by coming all the way from Dwaraka to Mithila. But now I want to take you one notch higher. There is always one notch higher. And what is that?
If you really want to serve Me. If you really want to worship Me then you cannot neglect those who have come with Me.