Blind prejudices
It is another case of not being able to see the woods for the trees
The wish the father to the thought
He is crotchety and full of conceits
He is wedded to his opinions
He has no adequate idea of the task
It is a piece of embittered old fogeyism
It is based purely on personal considerations
Arrogantly ignorant
He approaches every problem from a preconceived point of view