Many atheists are not as intrusive regarding their ethical views, you state in your question. Atheists can be very good and moral people, and most of them are, but . . . and that is where so many ignore history.
Atrocities have been committed on both sides. Atheist regime's under Mao Tse Tung killed 80 million of his own people. Stalin was responsible for purging 20 million Russians. Pol Pot's genocide murdered 2 million people, that amounted to 25% of the population of Cambodia. These deaths can rightfully be chalked up to Atheists. That being said, it is the exception, rather than the rule, but we cannot ignore history.
Atrocities in the name of religion, are just as horrible. Crusaders marched on Turks and Muslims, wholesale slaughter was the order of the day, in the name of God. Today we see ISIS committing atrocities in the name of Allah. Their goal is a Caliphate and world conquest. These incidences are aberrations of the teaching of Christ. Many Muslim scholars will tell you that Jihad is all about spiritual warfare. Atrocities have been committed on both sides and we cannot ignore history, or we will repeat it.
As far as intrusive behavior, in every day life. Most faiths teach their adherents to preach their teachings to the lost. A person on the receiving end of someone's zealous evangelism will often feel resentful and uncomfortable, while the evangelist will feel they are just sharing their faith, and doing God's work.
We see the teaching of Atheists in our Universities, Colleges, High Schools and Elementary Schools as just simple education. Yet people of faith and religion, see it as intrusive regarding their beliefs and faith in God. We all need to see both sides of the coin, before we start pointing fingers. Albert Einstein made a statement, that I really like.
"Science without religion is lame, religion without science is blind."
We need to ask ourselves some important questions. Where does our hope come from? Is there existence after this life? How do we justify suffering and pain? Religion gives many people comfort to these questions. Others are looking at a bleak picture of the universe. Maybe religionists just can't cope with such hopelessness.