The religions have? Or the people who have used and misused the religions have? If you want to blame religion, then by the same standard, these religions have conveyed great comfort, beneficence, and progress for the past 3000 years, as well. And since bad news tends to get more press than good, it is hard, if not impossible, to judge what the exact balance is.
We can speak of what might have been but this is what really is.
Fair enough. But then, by the same token, we cannot say, "None of those people would have suffered their fate if Christianity (Islam, Judaism, etc) did not exist."
How many wars have been fought in the name of Buddha? Buddhists may fight in wars but they don't fight for Buddha. I wonder how Buddhism has managed to avoid the Judeo-Christian blood baths?