I'm failing to understand why it's other players' fault you feel wronged. It was an error on the part of the developers, which by the way has been a thing for quite a while.
If someone's going around one shotting things, I really don't care, it's not like they've laid claim to the entire map. It's not a problem caused by people one shotting things, it's a problem cause from a new job dropping with really only one way to level it. So there's going to be a ton of blue mages in every corner of the (ARR) world grinding on overworld mobs. Naturally with finite mob spawns, there's going to be competition.

And what's with the mount complaint, anyway? 'Have to jump on a mount to find mobs'? What?
So you run around the world on foot then?