The loss of candor is grievous, and in my opinion it may yet prove to be mortal, because if we cannot discuss our problems in plain speech that describes reality, it is unlikely that we will be able to solve them.
The basis of Sufism is consideration of the hearts and feelings of others. If you haven't the will to gladden someone's heart, then at least beware lest you hurt someone's heart, for on our path, no sin exists but this.