The Wonder Girls members decided to disband the team because they love Wonder Girls so much
On January 26, 2017, JYP Entertainment officially announced that Wonder Girls will be disbanded, stating "We've discussed a lot about the girl group's future and the members decided to disband the team. Yubin and Hyerim, who've renewed their contracts will be active in various fields including singing and acting, while Yeeun and Sunmi resolved to leave JYP to pave new ways for their futures. We thank Wonder Girls' fans all over the world for having supported the girl group for the past 10 years."
I think many of k-pop fans never thought Wonder Girls would be disbanded. Frankly speaking, even people in the k-pop industry including me never predicted that Wonder Girls would be disbanded because the members have been on good terms and they gained a complete success with their recent song "Why so lonely" which was released in July 2016. Most of k-pop girl groups might never disband their teams if they're in a similar situation.
By the way, there was a good reason for the breakup of Wonder Girls. It has been 10 years since the girl group debuted, and the team has gained a huge popularity as a top class k-pop girl group, However, the k-pop world has changed so much and it's hard to say Wonder Girls is still the most popular girl group. You know, there are a lot of popular young k-pop girl groups such as TWICE, GFriend and Red Velvet. Of course, it's true that Wonder Girls showed off its undiminished power in the k-pop world by achieving a great success with "Why so lonely," but the Wonder Girls members know full well that their popularity will not last for ever. In this situation, they decided to leave when everything's perfect. In other words, they wanted to leave Wonder Girls as one of the most popular k-pop girl groups.
Well, some of you still might not understand why they made such as decision. However, you know, Wonder Girls has had many ups and downs since its debut. Hyuna has left the girl group for the first time as the original member of the team, while Sunye, who was the leader of the team suddenly got married at an early age. And after Sunye decided to leave the team, fans of Wonder Girls had to wait for the girl group's comeback for a long time. The Wonder Girls members didn't want to hurt their fans again, and they thought the best way to protect their fans was to disband the team because they knew they will not be able to release Wonder Girls' album very often.
You know, they've gotten old and it's time for them to think about their future, which means they can't just focus on Wonder Girls' group activities like they used to. Yeeun has a passion for songwriting and she wants to continue her singing career as a competent singer songwriter, while Sunmi, who's left the entertainment world once hopes to become more great solo singer. That's why they decided to leave Wonder Girls and make a fresh start.
I'm sorry such a great k-pop girl group decided to disband the team, but I support their choice because I'm sure it is both for the members and their fans. Let's wish Wonder Girls the best of luck in the future.