Because I think the majority of us berate ourselves too much. Well, we do, don't we? Here goes...
Whenever DS (age 3) has a mega-tantrum to the point where I feel like slapping the stroppiness out of him, I always make sure I:
(a) give him a second chance to be good (which always works, bless him); and
(b) end the whole episode with cuddles, kisses and reminders of how much I love him.