And they should be worried

It's unlikely that the attack was some random event that had nothing to do with this being an Arabic television outlet.  It could be. But best to assume that the attacker had other motives, and that could help track down the suspect and thwart other attempts at violence.

See how easy it is?  So next time a Muslim or Muslim convert walks into an office and opens fire in the name of Islam to honor the Prophet, can we stop banging our heads on the wall and wondering if it could be because the suspect could have played violent video games?  Could we then make the obvious first assumption and go from there?

I'm fine with it, as long as it's consistent.  If it isn't - either direction - then it's simply two sides of the bigotry coin.