Watching kpop survival shows, it's obvious how singing is like the least important when it comes to being a popular idol. Good vocalists always give the most to the performances, they are still the least liked by fans. (Totally shocked me in gp999 and boys planet as well) Expect when they are handsome enough (I love Taerae's voice/vocals, but lets be honest: he gained fans because of his visual not because of his vocal talent - which is sad -, otherwise Hui would be in his place).
And ofc when kpop companies see how is it in these shows , they gonna debut charismatic, visual dancers, instead of great singers.
Tbh, it's kinda sad and even undair but this is the kpop industry. It's pointless to search for something in it which is not there in the first place.