They’re different, I think that’s a fairer way of putting it. They express themselves differently and don’t necessarily act as you would expect them to.
You also have to remember a high number of them have been rescued, often over the age of 5 and have not had a good life up until then. You would be miserable too if you thought every male in the world was going to abuse you. There are some who never seem to get out of foster homes (black ones seem unpopular for some odd reason). But despite all that they are still loving and affectionate dogs.
If you want a good example of a dog that fitted the “completely rubbish” profile and is slowly coming out her shell have a look here:
https://www.facebook.com/profile.php?id=100064535748934
Ours still gets separation anxiety, I spoke to him in a weird voice just there and he bolted up the stairs. When we got him he didn’t know how to play either with us or other dogs. We got him when he was 2 1/2 and have had him for 3 1/2 years now and still find odd little quirks. And we think he was actually fairly well treated, he just wasn’t a pet.