They think that any construction of any port in the region will harm dubai. That's the reason UAE played a major role in the destruction of Lebonan, as Beirut was next good contender for the construction of international port. It has a history behind it.
That's the reason, why UAE expelled Pakistanis on massive scale, and teamed up with India to destroy CPEC. But, dear readers, this time they met iron balls. We can teach UAE a good lesson in a click, but we refrain because we are already in great grief over the destruction of many arab countries, so we have restrained till now.
But we love UAE, after all.