NAB spent the last several years arguing that satellite radio should be forced to pay these royalties. Prior to those hearings, satellite hadn't been paying, since they were arguing that they were another form of radio. Any lawyer worth their salt would have told NAB to support satellite radio as protection against something like this. But they didn't. They saw a chance to eliminate a competitor, and hoped to saddle them with an additional expense.
One of the first victims of their stupidity were the NAB member stations that were streaming on the Internet. Previously, they hadn't had to pay, either - which was a good thing for them, considering that most streams had their advertising removed from the stream, and weren't generally profitable on their own.
Their arguments as to why they shouldn't have to pay are outdated. They claim that they're giving free promotion to music, but how many terrestrial stations are actually giving exposure to new music? Seriously - how many stations in your town are currently recycling everyone's favorite hits from the 60s, 70s, 80s, and 90s? Radio knows that new music doesn't draw listeners - it's easier to take the free ride and give audiences the music they already know and love.
Radio should have to pay. Given NAB's size, it shouldn't be difficult to negotiate with SoundExchange for a lower rate.