It would be hypocritical of anyone to encourage celebration of something they disagree with or believe is false. I don't believe in the Easter Bunny, Tooth Fairy, Flying Spaghetti Monster and I can guaruntee you that I will insist on 'keeping it real' on those topics as well.
A main complaint here seems to be that criticisms are untrue or motivated by bias, although if this were true I am sure that all critics would have changed their minds due to the decency of Muslims who set out to dispel these untruths, instead what we find is many complaining that critics should not be allowed to speak.
I believe this is because they also know that criticism of Islam are valid, yet they are so entrenched in the 'complete way of life' that is Islam to want to face up to the complicated realities of addressing the problems that it causes. This is exactly how we, as Christians, have operated for decades and it is the same mentality that has lead to witch burnings, crusades and all other manners of cruelty that are supposedly vital for our religion, our people and our God.