Zereth Mortis was designed by the First Ones as a workshop OSRS gold to create afterlives. The automa, its inhabitants, have built everything that exists in the Shadowlands. It's a bizarre mysterious, alien-like place that defies any concept of reality or physical laws. The Jailer plans to utilize the mysteries of Zereth Mortis to reshape reality and bend it according to his evil will.
Completing various activities throughout the zone, such as exploring maps, discovering hidden treasures, and completing quest storylines will earn you an achievement, Unlocking the Secrets which allows you to fly rides in Zereth Mortis.
"Right today, in case want to maximize your chances to get the mount, it's in your best interest to repeat this experience every day for the most characters you can," Chimes wrote. "That's...mathematically correct, but not a great experience. We're aware of this and the positive side is that we're discussing this issue within the team and exploring possible solutions for holiday events in general."
Chimes is then able to say that even though changes are under consideration cheap RS gold, they weren't prepared to be ready for the Valentine's Day event. The easiest answer to the problem would be to simply boost the likelihood of dropping the mount, however it remains to be seen whether Blizzard decides to go down that path or come up with a different solution.