It is not for me to start any campaign. We have a gabernment who represent us and the country, don't we? Useless gabernment.
All governments grudgingly abide by this convention for the simple reason that it works both ways. It protects Singapore's diplomats while they go about their jobs abroad.
Without diplomatic immunity, Singaporean diplomats in our neighboring countries could well face various forms of persecution every time Singapore has a diplomatic spat with its neighbors.
If Singapore stood out from the crowd and refused to grant diplomatic immunity, then all countries around the world would retaliate by withdrawing immunity for all Singaporean diplomatic staff.
A similar situation exists with driving licenses. Most countries honor the driving license of another country for a specific period so that their citizens can enjoy the same privilege when they travel. If one country clamps down, other countries will retaliate accordingly and the common man suffers.