It wasn't a particular type of emotion being removed (only the negatives, or only the angry ones), both negative and tender-hearted emotional responses alike have been excised.
All evidence points towards this being a systematic removal on Luke's part.
Richard doesn't have a really good explanation, so he says, of why Luke does it. On the other hand, he does demonstrate that Luke is far more concerned with the emotional response of the people Jesus talks to than Jesus' response.
A survey of Jesus' emotional responses in the gospels moves us towards an understanding that his responses are those of Yhwh God, and not simply the human nature of the incarnate Son.
Weinandy's attack on Moltmann and others are rendered inert. A suffering God can save us from our suffering. It's only our Western logic that makes this tension an unresolvable one.