Dear Mr. Sawant,
It seems that staying in Saudi Arabia, you have restricted yourself too much. It seems you have forgotten to even display your emotions like happiness, brotherhood, oneness, etc. publicly. You make it seem as if celebrating a festival is a big crime.
Remember the adage "All work and no play makes Jack a dull boy." One's workplace is not supposed to be a detention camp where people are supposed to come, keep a straight face, and just do nothing but work and leave.
Only if there is some camaraderie between the staff will they actually enjoy their work and be more productive. Celebrating a festival like Diwali goes a long way in building up this spirit of brotherhood, unity, etc., and it gives the employees a feeling that their organization does not treat them as just machines but as human beings and does care for their happiness and well-being.
If you have any contrary opinions, you are free to follow them, but please do not try to impose your views on others. Do take care of your language while writing; it might sound offensive to others.