There's been a lot of backlash against underage idols in the industry. Particularly from ifans who like to baby them and say "kIdZ uNdEr 18 sHoUlDnT bE iDoLs". Yet contestants in My Teenage Girls and other U18 idols have proven they are more than capable to perform as professional idols. These two trainees from MTG killed this Monster cover and got 4/4 score from the judges. Even Irene/Seulgi could learn a thing or two from their acting and facial expressions.
One of the rookie idols who quickly trended a lot is Leeseo, maknae of IVE. Koreans who are are casual followers of kpop took notice of her and she's getting a lot of views on her fancams.
What they all have in common is that they are 14 years old. Obviously since they are still underage they should be protected and have more reasonable schedules, yet they can still pursue their dreams and earn a living. Unfortunately this generation that claims to stand for equality and tolerance are so openly hostile to people older and younger than them. It's open season against older fans, saying a lot of insults against them. And they want to push underage idols aside. It's no surprise, since most ifans are in their late teens/20s, so they discriminate against other ages.