I don't understand why someone would use BitWage to get ethereums.
For the same reason you use BitWage -- because they hate filthy fiat and believe in ETH.
Because if they get paid in Ether, store their wealth in Ether, and DAO companies accept Ether as a form of payment, that's a closed-loop economy right there

It's also not yet near any kind of store of wealth.. and supply is not fixed.. so it's likely to be a poor store of wealth.