When my unit chose to risk sacrificing himself to destroy Grima permanently, I was pleased with the ambiguous way they seemed to be handling the outcome. MU is missing and possibly dead, leaving the rest of the group to mourn, search, and hope for his return. This was good - it meant that the sacrifice was significant and it was up to me, as the player, to decide for myself whether MU would ever be found or if he even survived at all.
And then the character endings roll. So far, so good. After all is said and done, however, a brief cutscene occurs in which Chrom and Lissa find MU asleep/unconscious in a field, just like the beginning of the game. In seconds, all ambiguity was gone. They told me what happened to my avatar. They outright stated that his sacrifice had no consequences because of some love and friendship magic and that he would go on to live a happy life (or as happy a life as one could have with Tharja, anyway).
Why? Just why? Wasn't the non-sacrifice ending (allowing Chrom to deal the killing blow) in place for the crowd that wants definite happy endings and closure? Isn't the entire point of having an avatar that the player gets to choose what they are like, what choices they make, and what happens to them?