I'm referring to Muslim culture in this post, not the religion of Islam. I have researched this stuff enough to know that's an important distinction here.

What do you see as the difference between the two? I can't see one in your post. It seems like you're referring to Muslims generally. Islam is a very diverse religion, the claim that there is a unifying "Muslim culture" separate from Islam requires evidence. As it is, this needs a definition. What is Muslim culture? How is it different from things like the act of praying towards Mecca? It also needs a mechanism. How does Muslim culture make people into terrorists? Without those things it just sounds like you're attacking Islam.

Why is our culture responsible for say, the actions of Elliot Reed, but the 6-10 gunmen who executed almost 150 people were somehow completely, utterly disconnected from their culture? Explain THAT one to me.

Do you mean Elliot Rodger? Assuming you did, those who claim that culture is responsible for what he did have a definition of culture and a mechanism for how it affected Rodger. They point to values surrounding gender roles and relationships, they say that Rodger's immersion in those values interacted with his mental instability and led him to attack. This is different from what you seem to be doing and explains why you're getting so much flack. They're not assailing American culture broadly, they're pointing to a specific aspect of it. No one is using Rodger's actions to make an argument against fireworks on the 4th of July or malls. Without a clear definition of Muslim culture and some idea of why you think it's the cause of terrorism instead of other social, political, or economic factors, that's what it seems like you're doing.