So if someone, "T, "constantly makes an assertion, to the point they join a group devoted to said assertion..and you believe that assertion is false....That doesn't make you think "T" is full of baloney as far as said assertion? THAT makes no sense.
"I don't agree with your belief" != "I think you're full of baloney".
For example, I don't think you're full of baloney for having this attitude. I just think you've got it wrong, and I am politely disagreeing with you as a result.
By the way, I checked four online dictionaries, and they all defined baloney as being some form of nonsense - not merely that something was false. So, sure, some atheists might think religious beliefs are nonsense, and therefore baloney, but other atheists may simply think religious beliefs are false.