Complex sentence: Joseon scholars secretly used Ming era names even after that dynasty's collapse and many thought that Joseon should have been the legitimate successor of the Ming dynasty and Chinese civilization instead of the "barbaric" Qing.
Split into simpler sentences: Joseon scholars secretly used Ming era names even after that dynasty's collapse. Many thought that Joseon should have been the legitimate successor of the Ming dynasty and Chinese civilization instead of the "barbaric" Qing.