Yazid ibn Mu'awiyah... was he a good man?

Muawiya made yazid caliph during his life time knowing his son was evil person ..who was always drunk and induldged in illegal . What was ur (ra) insuring ? Was he insuring the power stays in his family at the cost of destruction of muslim ummah ? What good was he doing you muawiya lovers ..or he is ur father ? Abujahl was the worst enemy of prophet muhammad(pbuh) so was abu sufyan ....muawiya and yazid were enemies of both prophet and his family ..and destroyed muslim ummah .... Are u kidding ?? Have you got no brain ??