Thank you for your question. There was a group of people that were enemies of the Imams (as) in Kufa but generally speaking Kufa has been a stronghold of the Shia and that is why Imam Ali (as) chose it as his capital. There were Shia in Kufa that joined Imam Husayn (as) and others that were prevented through imprisonment. The hadith of Ahl al-Bayt (as) were also wide spread in Kufa during the lives of the later Imams and the Shii Kufan population was subject to oppression many times during the reigns of the various caliphs. So the premise for the question is not accurate as it is one sided.
May you always be successful.