I read that John Adams didn't attend Jefferson's, maybe out of spite. But, it's been a long while since the last time it happened. It is optically a more smooth and peaceful transition, if the outgoing guy attends.
Not only a smooth and peaceful transition but a true concession. Trump seems to keep playing to his base that the election was stolen and it isn't over. Perhaps to incite more violence.
But really I think it comes down to he can't handle losing. Can't even comprehend it. Can't admit it. So he can't go there when it destroys his mind that it's even happening.
I'M NOT SURE HOW YOU MISSED MY COMPLETE LACK OF CLASS DURING THE DEBATES; BUT IF YOU HAVE ANY DOUBTS
I'M HERE TO LET YOU KNOW I'M TOO SMALL A PERSON TO ATTEND THE INAUGURATION