I think it is interesting how few people want to talk about this issue. From where I'm standing this is probably the single biggest issue holding bitcoin from being adopted as a mainstream currency. CC's pay you to use them. Paypal is free. Bitcoin COSTS money. No one seems to want to admit that this is a problem.
If I take my salary in bitcoin, then using bitcoin no longer has this "exchange fee" that you keep mentioning. Instead, there is an "exchagne fee" to get USD that I can then spend to pay my credit card bill (which if I'm carrying a balance also has an "interest fee"). Or instead I could just directly spend the bitcoins, and avoid the "exchange fee" and "interest fee". I might even find merchants that offer lower prices for bitcoin payments, saving me even more. And the bitcoins that I don't immediately spend intrinsicallly increase in value over time due to deflation! Try that with your credit card and USD.
Seems people won't want to use USD and credit cards because of all these immediate fees that are avoided with bitcoins.