Being a "rules kind of guy", I support a rescue's right (and responsibility)to make rules for its organization. It has, however, been my experience that organizations that refuse to occasionally revisit the rules, no matter the circumstances, are about the organization and not the product (in this case, the product is the pup). That doesn't mean that the rules are wrong or that they have to change, only that every dog and every client deserves every effort to find a good home.
Efficiently developing rules for any situation allows for the potential that not every client will fit the desired (or expected) mold, but they may make a good fit none the less. I am not saying that a rescue must change its rules, only that a refusal to at least consider a potential client suggests that its not about the perfect home for the homeless pup, its about the rescue organization. For that reason, my personal search for a pup includes only a cursory level of research of rescue organizations.