User blog comment:B214/Talk About What You Want! 2/@comment-74.77.52.225-20140716184143/@comment-1359322-20140716232809

It's not that Rias didn't try to fix it, she tried and she did succeed to a certain point, but at that certain point, Rias hit the limit of what she can do.

After all most of Rias' servants issues are out of her hands. Akeno's issue was with Baraqiel, Koneko was with Kuroka, Kiba with the Excalibur and Gasper, well Gasper was just a complete shut-in back then because he couldn't control his powers.

Majority of this issues are private issues and some of it may even cause problems for the Underworld like Kiba's, Rias had her hands tied too. If she tried to forcefully solve it, it would become an order instead, and everything she worked on to form a bond with them would crumble immediately.

Plus, she has her own issues as well, her engagement with Riser. So Rias herself was also at a state where she couldn't overcome her own problem. Then adding to the issues is that Rias is too kind, which ends up making it harder on her servants to overcome their issues. Akeno, Koneko and Gasper might end up doubting themselves because they might fear that Rias is the only one that can accept them as they are, while on Kiba, it might remind him of his past allies. So Rias' kindness which was what that rescued her servants, also became a barrier for them on their personal issues.