You're focusing only on Catholicism there. Religion is in fact more than just the Roman Catholics, and focusing only on the largest US religion is fairly narrowminded. The larger the group, the more nutjobs it has. Once atheism gets huge, atheist nutjobs will abound.
Further, those are the morals set down by the religion. In any community, there will come to exist an established set of rules which dictate what is right and what is wrong. The fact that you're saying that their morals, their sense of right and wrong are flawed isn't really targeting how the belief in God or gods is harmful to human beings.
Regardless of what a people believe in, deity or otherwise, it can lead to negative moral values. Those who believe in only money will prize it above all else. Should we then decide that money should not exist? Or should we attempt to alter the moral code of those people?
Belief in God doesn't make people stupid. Blind belief does. However, blind followers exist not only for religion but for many other things as well. Zealots need not be merely religious.