I think it's understood that many are in various stages of migrating away from being witlesses. Most of them know the religion is wrong, and they feel inside that they are being made witless by the religion doing their thinking for them. Many are still active but beginning to question whether the religion is really for them. Understanding that the religion is bad is important for them, including seeing the bad effects it has had on people.
I don't see widespread problems with people putting up valid posts and getting trashed. People that are new here are usually in the early stages of leaving the washtowel, and some become Christians while others become atheists. True, there are always going to be a few trolls that put out rubbish--along with a few that think their business is trying to round up apostates and get them back into the cancer. Still others will post something they sincerely believe is the truth, but comes straight from the washtowel articles or a legend they are spreading. For these, valid criticism of their ideas is important; otherwise, they are never going to see the real truth.
Remember--to the deluded, the truth is never attractive at the time. However, once someone realizes they were in a lie, the truth comes to be more attractive. It's only the person that positively refuses to do their own thinking, or those whose livelihoods depend on others believing that lie, that are truly offended in a lasting manner by the truth.