Whilst the lack of communication is negligent and I doubt anyone on this forum can speak for Oman, the root cause of this delay is not likely to be Oman's fault. A Xiamen plane experienced a crash landing at Manilla earlier this week, fortunately it appears there were no casualties despite it being a serious incident.
This has resulted in the runway at Manilla being closed for 36 hours and thousands of crew, planes and passengers being disrupted throughout the region. I can't comment on the specifics of the delay for Oman but with a 36 hour closure of a major international airport plus inbound aircraft inflight being diverted elsewhere from MNL and planes trapped on the ground at MNL many airlines and the airport operations team will be doing their best to try to restore normal service as quickly and safely as possible for all concerned.
Whilst the delay and lack of communication must be frustrating, a sense of perspective would clearly be useful here, and for all involved in the Xiamen incident must be truly grateful to have escaped with their lives.
For a very technical write up on the incident plus some pics see
Accident: Xiamen B738 at Manila on Aug 16th 2018, runway excursion on landing