This does not mean that barbs will be or should be the go to MF class since ranged classes like wizard will typically have a lot of tools to keep them alive while still dealing damage (teleport, ranged AoE + slows, etc.) or could have a higher kill rate in general. However, should you choose to level a barb, with the right spec, you can be pretty efficient at MF without needing to level up a second toon for it.
Here's the build I'm thinking of
I think dw'ing mighty weapons is the route to go. The basic plan of action is to generate fury quickly then spam hammer to kill off everything. Earthquake is in there for dire situations when you need to clear a large pack quickly. Also, since weapons currently do not give MF iirc, a 1 hand plus shield might be a decent option to up survivability and magic find at the loss of damage
If you have any suggestions or thoughts, I'd love to hear them