At one time many years ago, the exploits of the royalty were not so royal and many were able to get away with misdeeds that need no repeating.
TDM made an important change to the laws and today only the Sultans and the Agong cannot be sued or charged.
In a constitutional monarchy, where members of the royalty do mix with ordinary citizens to socialise and do business it is important for a uniform set of rules to apply or there can be chaos.
I am sure you would have read that members of the royal family are fined regularly for speeding.
So this article in malaysiakini is a little surprising Pakatan willing to 'return royal immunity' .
Unlike the UK where there is only one royal family, we have many different royal families.
I think the present law is appropriate. No Ruler should be charged in connection with the discharge of his official duties.