Shaykh Muqbil bin Haadee (rahimahullaah) stated about Shaykh Rabee bin Haadee:

By the praise of Allaah, Ahl al-Sunnah filter out the society with a filtering. Shaykh Rabee, "There will never cease to be a faction from y Ummah, manifestly upon the truth. They will not be harmed by those who oppose them, nor abandone them, until the command of Allaah arrives and they are upon that." Shaykh Rabee' [is from amongst these] in the land of the Haramayn and Najd, yes, by the praise of Allaah, he filters out the Hizbiyyeen with a filtering and he makes clear what they are upon.

Source: In the cassette (شريط ثناء العلماء على الشيخ ربيع - تسجيلات منهاج السنّة) and as published in (الثناء البديع من العلماء على الشيخ ربيع) by Shaykh Khalid al-Dhufayree. This is why Shaykh Rabee is hated by the Hizbiyyeen. They have taken a leaf out of the book of the Ash'aris of 8th century Shaam and Egypt with respect to Shaykh al-Islaam Ibn Taymiyyah, they tried to malign him, attack him, revile him, slander him and even portray him as a kaafir. And we find that a portion of this has been set aside for Shaykh Rabee by the Hizbiyyeen, for no other reason except that he is caller to the way of the Salaf in creed and methodology and refuting and shunning whatever opposes it from innovated methodologies, the jamaa'aat upon them and the figureheads leading them. Shaykh Rabee' has exposed the jamaa'aat of hizbiyyah of the 20th century and the great evil they have brought upon the Ummah with their innovated fikr (thought, ideology) by which they clash with methodology of the Prophets in da'wah to Allaah. It is for this reason alone that he is maligned and attacked as Shaykh Ibn al-Uthaymeen made clear (see here).