Gun related death dwarfs that caused by terrorists here. Why is it the public goes crazy if it is connected to terrorism and yawns and does nothing about guns and gun related deaths in this society?
If you are actually interested in an answer to that question I can give you one. You made a comparison here of two things:
1. Terrorism, terrorists
2. Guns
In number 1 (terrorism, terrorists) we are talking about people making decisions to kill. In number 2 (guns) we are talking about an inanimate object which cannot make a decision. It is a tool not a killer.
Terrorists are killers, guns are not. Only people can be killers. Therefore your comparison fails. In order to make a legitimate comparison you have to compare the people.
So who are the people involved in your comparison? First there are terrorists who are extremist Muslims. In the second we have a gay black man who was also an extremist which became evident once he gave the media his manifesto. We know he was an extremist because he wanted to start a race war.
So, the issue here is not guns but extremists. The conversation should be what are we going to do about extremists. No reasonable person would be distracted by guns when extremism is the real issue.