So what thats just one good example of someone who was true to his vows. The real question is why are married men excluded. In fact why are women excluded as well. It was the women who were more loyal to Christ at the time of his death. The men ran.
Priests act in the person of Christ, so unmarried men stand in imitation of Christ. They also represent a sign to the culture of sacrifice with the hope of the life to come. Finally, there are practical reasons. As St. Paul says, the married man is busy with his wife's concerns. His heart is divided.
In fact why are women excluded as well.
The priest acts in the person of Christ. Christ was a male, he is the eternal high priest, and he chose males as his priests/bishops, so priests must be male.
So, in your opinion, Christ made a stupid mistake in choosing twelve males as His Apostles.
Too bad He didn't have you around back then to straighten Him out.
Or . . . there is the outside possibility that He knew more than you do.
Just putting that out there.
I have friends who went to Catholic schools too. You would think they would know their faith better than the next person, but they don't. If you don't understand the above, you have a lot to learn, and FR is not the best place to learn it.