Yes, justice just isn't worth going to the trouble and time, is it?
It's not as if I don't notice the sarcasm, but let me answer anyway. We have to pick our battles. While this impeachment was going on, any other Congressional business would come to a halt. Even if the K. was impeached in the House, nothing would happen to him unless he was also convicted by a 2/3 majority in the Senate. So, it would be a show trial with no real possibility of effect.
And, I believe that Trump can just replace the guy after he is inaugurated. Or, if the appointment is for a fixed term, he can find plenty of reasons to request his resignation.