Intelligent people have the ability to pick up the best even from the worst.
There is a saying that an intelligent man can pick up nectar from a stock of poison, can accept gold even from a filthy place, can accept a good wife even from an low family and can accept a good lesson even from a man or a teacher who comes from the lowest layers of the society.
People from less developed countries come to foreign countries for higher technological knowledge. Similarly, we should take useful knowledge from anywhere. Utility is the principle.