We have a professor who really does not like when students are late to his class or leave early. For example, his class ends at the same time many of us have a class that is starting about a mile away. He has scolded us for leaving his class early to go there, calling it "a disruption."
However, he does not set a very good example for us. He arrives late to his own class when he has guest speakers taking his place.
I think a way to gain a lot of respect in this world is to practice what you preach.