How to understand “punishment of children for the parents’ sins”? Because not tsadikim parents “cause” punishment for their children, how children can and should honor those parents?

Honouring our parents is a commandment form Torah and one of the Ten Commandments, regardless to their good or bad behaviour. The verse (in the Ten Commandments) which teaches that sons are punished for their fathers sins is explained in the Talmud (Brachot 7a) to be only in case the child follows his fathers bad deeds.