unneutered dog upsets neutered dog

Question
The neighborhood park is a leashed dog only park but someone would bring their unneutured beagle off leash and it would offend leashed dogs by "humping" them.  The owner tells everyone it is a dominance and not an aggressive behavior, basically "it is okay, normal".  They will not neuter their dog.  They believe neutering the dog will reduce its lifespan and refused to neuter their dog.  My 9 year old neutered jack russell terrier thinks the "humping" behavior is inappropriate and gets upset.  Currently, I take my dog home when this dogs appears. Any suggestions would help.  I heard that unneutered dogs are also allowed at dog parks (designated off leashed areas for dogs) I was also hoping for advice on how to prevent my neutered jack russell terrier for getting upset at unneutered dogs at off leashed dog parks.  Please let me know.  Thank you

Answer
There is no reasoning with obnoxious people that break the rules.  I would complain to animal control and whoever if responsible fro the park about the dog running loose.  I have no use for people that allow unneutered dogs run loose.  As for shortening the dog's life, it is just the opposite.  

You might try the dog park at least once.  I think many of them are well run and nobody is allowed to let their dogs be a problem.