Why are some atheists so angry when they see people believing in fairy tales?

Answer by Kris Rosvold:

I have absolutely no problem with folks who believe in fairy tails, or in fairies' tales for that matter.

Where I have a problem is when they try to write laws which require ALL OF US to act like we believe those fairy tales, especially if those fairies and their tails demand that we denigrate and marginalize my fellow Citizens.

Since we've had +200 years of fairy tales (and tails) being used that way there is a problem here.

Now, if You need to believe the fairy tales which assert that fairies have tails, I'm good with that. 

If OTOH you want to insist that I believe that fairies have tales which tell of tails or that it's "somehow" *waves hands vehemently in the air* A OK to denigrate, protest against, or arbitrarily and capriciously delete the Rights of, my fellow Citizens then I'm going to be forced to laugh in your face after a very brief interlude applying Occam's Razor.

Why are some atheists so angry when they see people believing in fairy tales?