You're generalizing beliefs which is preposterous; are you going to argue with an 8 year old who still believes in the tooth fairy? Some beliefs are extremely harmful- eradicate those. But others simply are not. Or they're in a "gray" area. If someone chooses to debate with you go ahead- but the idea that you need to eradicate all beliefs that YOU feel are wrong makes no sense.
So you weren't generalising beliefs when you said 'what's wrong with letting people have their beliefs?'
At least you now seem to be conceding the point that it's wrong to just let people have some beliefs.
Nobody here wants to eradicate beliefs that they simply
feel are wrong but some beliefs do cause harm and need to be challenged. Some of these beliefs are rooted in religion.
Generally (there's that word again) the God beliefs that religions peddle are harmful. Even if you balance that with some proposed benefit that comes from religion there is very little justification for maintaining the negative aspects of their beliefs.
There is no additional benefit from peddling a God that created the Universe, and loves everyone, and wants us to be nice to each other AND just happens to think that being gay is bad. Or that just happens to also be offended by life-saving medicine.
Why not simply stick with a God that created the universe, loves everyone blahblahblah and doesn't have a problem with gays or medicine?
Even if you think religion is mostly good, accepting a God that is even mostly good but 10% a complete **** that does horrible things is just unnecessary. Bearing in mind that the religions themselves have invented and embraced the ****ish parts just as much as the good parts. To what end?
Either you believe the nonsense that some ancient people had a direct line to the mind of a higher intelligence that communicated his pet peeves to them or you accept that the churches are maintaining these negative aspects of their religions because they are simply nasty ****s.