Is it because they fear to be included?
Is it because they know that they are included and want to show others that they are not?
Is it because they still have animal instincts to attack and distroy?
Is it because they are ignorant and/or with a limitted understanding of what we are and where we stand?
Is it insecurity?
Are they afraid to discover?
Are they affraid to be attacked?
Are they affraid to be contaminated?
For whatever reason... I cannot think of any inteligent one...let me know if you know!