It is true to say that too many people are protected under the diplomatic immunity. This is evidenced by Turkey arresting the UN judge in the violation of diplomatic immunity. This was the right thing to do, since lots of people have taken granted of their positions to be unfair to the people with no say.
Diplomatic immunity should offer some protection, especially for freedom of speech, assembly or association situations. I don't agree with the criminal immunity for violent crimes, theft, rape or assault. But it may be that there's not a way to differentiate and so it's just a blanket protection for anything that would normally result in an arrest or detainment.
Too many people are protected under diplomatic immunity, and the entire concept is a complete and utter joke. There is no rational basis or reason for this kind of immunity to exist. Law and order that applies to the little peon's like me should equally apply in force and effect to foreign VIP's.
No, there are not too many people protected under diplomatic immunity, because without immunity there would be no way to have officials from other governments working around the world. People who decide to go into foreign service have to know that they're going to be safe. They need to know that they will not be subject to political arrests. It is not abused.