If you think a certain topic is stupid or has no evidence or foundation, simply stay out of it.
How about when someone says, "Obama is a Kenyan! His birth certificate is fake!"
That topic is stupid and has no evidence or foundation to support it. But we should "simply stay out of it?" We should let this person continue to spew beliefs that are harmful and not based on evidence continue to do so and possibly mislead others? We should let them go unchallenged without demanding evidence for their extraordinary claim?
Hell no. I will not stand by and I will not stay out of it.
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke (supposedly)