All agencies suck in that regards. The official reason is "Technical Issues"
They say the filtering criteria are objective but they are more than 80% subjective, as sets of photos from similar sets with same settings sometimes get fully approved and some other times fully rejected. That's why I am back uploading to Alamy as they give full creative freedom to the photographers.
At the end, it must be the client who decides what's good and what is not. ;)

Huge thank you!

!PIZZA
!BBH