No one wants to bring anything or anyone onto their property that is likely to be a reason to have their insurance costs increase or even be made unavailable. A buddy of mine has 2 pit bulls. One is sweet as can be. The other would take a leg off. The problem is you never know what will set this breed of animal off. It might never happen, it could be a small kid acting normally looking like prey to the dog. And yes, you can have great dogs, but others have proved this breed to be a financial liability so many refuse to allow them.
Also keep in mind that EVERY pet owner always says "my dog is so sweet and quiet and never barks or destroys anything". The best bet for you (if you are renting) is to actually offer to bring your dogs over to the owners property so they can see how your dogs really act.
Because of: Insurance reasons...maintance of home....barking problems...etc,,
Being an animal lover myself I can understand the frustration that one has with trying to find a roof over their head with having their dear pet with them.
Keep looking, maybe you will be lucky and find another person who has pit bulls and wouldn't mind renting to you.
That statement has been given at many crime scenes involving pit bulls mauling children.
Keep looking is all I can say. I wouldn't allow them on my property if I was a landlord just for the liability factor