If that was all there was to it, I would agree.
However, that's missing the huge asymmetry at play here: money. Specifically, the NRA is an industry-funded group that has lots of it, and the people who's family members have been victims of gun violence don't.
If this was a spat between, say, Google and Oracle, each of which has boatloads of money to buy the competitor's advertising spots, no one would care.
But this story feels scummy because it's a human story, one where the little guy is fighting a noble cause but is being shaken down by organizations who write weekly checks larger than some of these people will see in their lifetime.
If you pretend that money doesn't create an asymmetry, then yes, you being upset this way but not the other is all relative.