Some reasons for Orthros:
- It is the daily morning service (not special to Sundays), and the days are much better, IMO, when Orthros takes place.
- Orthros is a terrific teaching service. You can learn much about our view on the Resurrection, the Saint(s) and Feast(s) of the day, and much more by attending Orthros. It is the original Christian bible study in a way.
- The priest needs to be there 30+ minutes before Divine Liturgy anyway, to vest, prepare the gifts, and be ready for Divine Liturgy. Adding the Orthros is not much of a sacrifice, when understood in this context.
- Orthros more than most services reinforces what and who (or Who) we celebrate that particular day.
Personally, I'm 100% against having Church school, set-up time, choir practice, etc. during ANY divine service - Orthros, Liturgy, Vespers, Paraklesis, etc. Thankfully, our parish has a longstanding rule against having any activities during Church time.