For Mordechai ... was approved by most of his brethren. He sought the good of his people and spoke in peace to all their descendants (Esther 10:3).
The great Mordechai, who saved the Jewish people from total annihilation, won the approval of only most of his brethren. Most, but not all.
Some people need to be liked by everyone. If one person out of several hundred does not approve of them, they are devastated. They are likely to become "people pleasers," going out of their way to obtain universal approval.
This attitude comes from low self-esteem. People who feel secure about themselves believe that they are generally likable and do not feel threatened if one or more people does not like them. They realize that some personalities are simply incompatible with certain other personalities. The "chemistry" between two people may be of such a nature that one person simply does not like the other, but that need not be a reflection on the latter's worth.
People who are insecure and feel unlikable expect to be rejected. They therefore interpret innocent comments or gestures as confirmations of their unlikability. Since they fear such "rejections," they do things in order to be liked, in other words, they try to "buy" affection.
Mordechai sought everyone's welfare and spoke peace fully to all, but he was not perturbed that he did not achieve universal approval. If some did not approve of him, that was their problem, not his.