The law only covers those who "create" virtual currency. E.g. Linden Labs for SLL. I don't see how this can cover miners, who are "granted" virtual currency. I think you are drawing conclusions far too soon here.
c. De-Centralized Virtual Currencies
A final type of convertible virtual currency activity involves a de-centralized convertible virtual currency (1) that has no central repository and no single administrator, and (2) that persons may obtain by their own computing or manufacturing effort.
A person that creates units of this convertible virtual currency and uses it to purchase real or virtual goods and services is a user of the convertible virtual currency and not subject to regulation as a money transmitter. By contrast, a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter. In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency.
See my emphasis. This is while not crystal clear but it is difficult to interpret any other way than as
bitcoin miners are money transmitters if they sell for fiat. You can interpret it as you like, but what is important is how judges and regulators will interpret it and you can bet they will not be trying their best to bend over in favor of miners, the opposite is more likely.
However, selling for fiat on an exchange is unlikely to make the miner a "money transmitter", because "money transmitting" function is performed in this case by the exchange.