Oh dear, you're not a happy bunny.
You found the perfect dog? Quite a statement,

(Not a great website for pets that one - however guess you get the odd quality dog/pup on there) why was this dog perfect for you? It must have ticked a lot of boxes for you, with regards to its health, temperament, age and you being the right home for its breed traits and character, so if you feel so strongly that everything was right, how did people so easily dissuade you? **shrugging shoulders**
TBH no dog would be my perfect dog until I'd met it though, regardless of anything else.
Their points for not wanting the dog, seems to have over shadowed yours for having it, knowledge is only dangerous if not used correctly, was theirs not right? If so you should have corrected it, or did they say things you did not want to hear?
If the dog was everything you think it was, then I wouldn't listen.......the fact you turned the dog down, makes me think perhaps they made a valid point?........... Perhaps?
Just to make you feel a little better, perhaps it wasn't the perfect dog, we all get pulled in by cute photo's, sometimes we need a strong no! from others........ I might be wrong but, maybe in the long run they did you a favour?