Most Congolese bandleaders were conservative at that time and I think that they were fearing to try something new. You had based in Gombe who were making that kind of succes back in the 70s and 80s. But it was seen as foreign and it were mostly white people living in Kinshasa visiting them and those who were rich. For example the band Bobongo Stars, which had artists like Al Nzimbi, Shakara Mutela and the late Ondoma Motema who later played for Quartier Latin.
Papa Wemba was lucky that he was on his prime at that time (1977-1982), when you are on that level, the public will mostly always accept everything you release on the market.