Religious discussions (particularly on the internet) rarely end well. No matter what forum, someone will bring up the ways religion has been perverted to propagate fraud for someone's financial gain, or how many people have died because of arguments that have led to violence that have led to wars over religious differences, or some other list of atrocities. And, nearly always, someone will posit that religion itself is the cause of those travesties, arguing they would not have happened if religion had not existed, and therefore, the world would be a much better place, and indeed would have been a much better place for all of history, if religion didn't exist.
It's a hurtful thing to say to someone of faith, that the world would be a better place without something that you believe to be important. I don't think it's necessarily said with the intent to be hurtful. It's just an expression of their opinion.
Because opinions differ to such a degree, however, it's considered "conventional wisdom" that, to avoid hurt feelings, one simply does not discuss religion.
I've thought about this, though, and something occurs to me. If I were Satan, and I wanted to stop people from drawing closer to God, it seems that one very effective way to do this would be to stop people from talking about Him. I think that spreading it around that it was somehow "impolite" to talk about religion might be a good way to make people stop talking about it. In fact, it might have the added bonus of making people expect a religious discussion to be impolite before it even began, to make them less likely to respect another's point of view (even if they disagree with it) and more likely to use absolute statements that are hurtful and mean, perhaps without even realizing it.
So that means the only appropriate response is to talk about it.
The argument goes that religion is the cause of so much evil and horror in the world, leading to many of the wars in history. However, I look at our current government. It has ruled under a policy of not governing according to a religion. And yet, it has had plenty of opportunity to wage wars for different reasons. So to suggest that wars were caused by religion would also suggest that, without religion, the wars wouldn't exist. And yet, mankind seems to find plenty of reason to wage war outside of religion.
Some people point to the instances of people using religious influence to swindle people out of money for their own personal gain, or even violations of person. This, too, has plenty of evidences outside of religion to be considered a flaw of religion itself.
The very argument that religion should be thrown out based on these examples is flawed anyway. It is an extreme solution that focuses on the negatives of people misusing the tool. One could make the same argument with governments. Or public schools. Or armies. Or the Boy Scouts. Or the internet. Guns. Television. Oil. You name it; somebody has used it to hurt someone. Maybe even lots of people. Maybe started wars over it. And yet to say "it" is bad is just scapegoating at best.
I'm not sure why someone would say the world would be better off without religion. Maybe it's scapegoating. Maybe it's just that they don't like it and would rather not hear about it anymore (akin to me saying "The world would be better off without rap music," no matter how many people like it). Maybe it really is an attempt to say something so extreme and hurtful that it closes off any further conversation. It's hard to say, considering a statement like that does close the door to any meaningful dialog.
Which, unfortunately, is probably very pleasing to a certain enemy to all righteousness...