What will cause a fair amount of people to move on from this mode a bit quicker is the fact that the mount is much easier (faster) to acquire than previous rewards.
Whereas everything in the 3-way Frontlines required your GC/team to defeat both of the other teams, here your odds are about an even 50/50 split. I imagine it is an even quicker obtainable achievement for some if they were on a particularly "difficult" GC back then.
