Because of their 'privilege' they mismanaged the government, were ignorant (or worse) of the plight of the people of the nation, and could have cared even less. That was similar, if not exactly like, the other absolute monarchs in Europe.
That's quite a generalisation. Did it also, possibly, have anything to do with the judicial murder of the reigning Bourbon monarch and his wife, and the death by wilful neglect (if not worse) of their son? Not to mention the murder of thousands of citzens of France.
Do you mean to suggest another word when you place the word 'privilege' in inverted commas? Is it perhaps that you think the Bourbons were not privileged in some regard. Or are you quoting from somewhere?