There is no problem receiving monthly salary in btc IMO and for my use. The employer's should be flexible enough to control the constant fluctuation though. Also that won't happen unless BTC goes mainstream so there wouldn't even be a need for exchanges.
Bitcoin being in the mainstream is still too far in the future. But I hope it happens in our lifetime so we can have a choice in what currency we want to use. We can start ignoring fiat if that happens and we will be free from never ending inflation of fiat.
Not everyone will prefer to use bitcoins in future as there will be many people who will prefer to use paper money as they find it more comfortable to use.