You miss some key points there User so let me fix it for you.

Class = weapon/learning of abilities and free application of most learned abilities
Job = role/strengthening of abilities that revolve around a central party aspect (tank/dd/support/healer) with a loss of abilities that do not function within the stated party aspect (ie: dd will not get healing abilities)

When you dumb it down to a few words then yes you can make it seem like the apocalypse is going to happen to the class system, but when you actually define the system then you might realize that its not as crazy as you think. Just saying.