Let's review some of the examples in GGP:
> "My dog would never bite. He just snarls and snaps like that when he's nervous."
If you ever hear this, the dog is being socialized in a bad, counterproductive way before your very eyes. The owner is ignoring manifestly severe distress, as well as generally unacceptable behavior in public.
> "My dog is a good dog at heart, but she's a rescue so you have to make allowances."
The word ‘allowances’ here is kinda strong, in that it sounds like you're not only giving up on eliminating certain negative behaviors/feelings in your dog, but also in managing them.
But it's really close to something that I think is fair to say, which is that you can't expect your dog to instantly recover from trauma, and that you will have to make gradual progress on teaching your dog that the world is safe for them and how you expect them to behave in it. At the same time, it's your job to manage those behaviors along the way, so I'm not sure that counts as ‘making allowances’ in the sense of simply permitting otherwise unacceptable behavior. So it might be fair to give that one to the GGP, too.
> "My dog is only growling because you are showing fear."
This is useless information even if it's true, and it pushes responsibility for the dog's behavior and comfort onto others (probably including random strangers, given the character of the examples). This is poor socialization in action again.
(Aside: growling is good. It is good for dogs to give warning. You probably want to address the thing they're growling about (food possessiveness, fear, anxiety, mistrust of strangers), which may not be good. But you probably don't want to suppress growling per se or treat growling as bad behavior. That's a good way to get a less predictable dog.)
> "If you got bit, you must have done something to the dog. No dog bites without good reason."
If someone says this about their own dog, they're showing a stunning level of disinterest in their own dog's behavior, comfort, and impact on others. If someone tells you your dog bit them, you need to be very interested in all of the details so you can figure out what was going on and what you need to do about it.