The Muhaddith, the Mujaahid Scholar, al-‘Allaamah, ash-Shaykh Rabee’ b. Haadee al-Madkhalee (hafidhahullaah) mentions:
فما كشف عوار أهل البدع وهتك أستارهم إلا أئمة الحديث، والعلماء من فقهاء وغيرهم تبع لهم وعيال عليهم في هذا الباب العظيم؛ لأنّ هذا اختصاصهم والمعول في كل فنّ على أهله المتخصصين فيه وهذا من البدهيات عند العلماء وعقلاء البشر.
So the faults of the people of innovations were not uncovered and exposed except by the Imaams of Ahlul-Hadeeth. And as for the 'Ulamaa (Scholars) from the Fuqahaa (the Jurists) and others besides them then they would follow them and refer back to them in this great field (of knowledge of Jarh wa Ta'deel). That is due to the fact that this is their specialty, so the return or the reference point in every Fann (expertise and speciality) are the specialists in it, and this is from the most elementary and obvious matters with the scholars and the intelligent people.
Reference: Majmoo' Kutub wa Rasaa'il wa Fataawa of Shaykh Rabee' (Hafidhahullaah), volume 9, p.78, Daar Imaam Ahmad printers.
Translation by Aboo Abdillaah Bilaal Hussain al-Kashmiree.