Is it now Fard(Obligatory) on the part of an Islamic leader or King to demolish shrines of pious people in the context of the following Hadith.
"Abu'l-Hayyaj al-Asadi told that 'Ali (b. Abu Talib) said to him: Should I not send you on the same mission as Allah's Messenger (may peace be upon him) sent me? Do not leave an image without obliterating it, or a high grave without levelling It. This hadith has been reported by Habib with the same chain of transmitters and he said: (Do not leave) a picture without obliterating it." [Sahih Muslim 2:2115]
Rasoolullah(SAW) sent Ali(RA) to level the graves. The maximum allowed height is one span as compared to the surrounding area as mentioned in other hadiths.
Today many people who get income from shrines or have vested interests give flimsy excuses in making brilliant graves. All such graves, Dargahs, Rozas are clearly against these hadiths of the Prophet(SAW).
"Jabir said: Allah's Messenger (may peace be upon him) forbade (made haraam) that the graves should be plastered or they be used as sitting places (for the people), or a building should be built over them." [Sahih Muslim 2:2116-8]
The Messenger of Allah (SAW) the giver of the best guidance made haraam making graves Pucca or building structures over them.
“Beware of those who preceded you and used to take the graves of their prophets and righteous men as places of worship, but you must not take graves as mosques; I forbid you to do that.” (Sahih Muslim)
“May Allah’s curse be on the Jews for they built the places of worship at the graves of their Prophets.” (Sahih Bukhari)
“May Allah curse the Jews and Christians for they built the places of worship at the graves of their Prophets.” (Sahih Bukhari)
“If any religious man dies amongst those people they would build a place of worship at his grave and make these pictures in it. They will be the worst creature in the sight of Allah on the Day of Resurrection.” (Sahih Bukhari)
“Do not sit on the graves and do not pray facing towards them.” (Sahih Bukhari)
Quran - 1:5 You (Alone) we worship, and you (Alone) we ask for help (for each and everything).
Also, as a side question, What are the concerned organization or authority which is entrusted with the pious work of the prophet pbuh of demolishing such illegal Shrines?