LOL.... Khawarij and shaitan are on the same page...... Both mourn the day Prophet Muhammadصلى الله عليه وسلم came into this world.......
If you can celebrate mothers day, pakistan day, saudi national day, why not the birthday of Prophet Muhammad صلى الله عليه وسلم?
There answer will be they are not associated with religion... so the logical answer to that would be celebrate it as a world Event not as a religious event.
Why create divide? why call muslims mushrik and biddati? when you have the option to disaasociate this event from religion and celebrate it then.