Bullshit eh.
First of all, there may well be a time when you need to approach your dog in such a situation.
Say he was chilling in his bed and you noticed that he had picked up a glass for example and carried it into his bed.
Would you still leave him alone?
What if the dog was eating dinner and you fancied a hot chocolate, went to get the powder but accidentally dropped it and a load of cocoa powder landed in your dogs food.
Would you take the bowl off him?
If you have never taught your dog to willingly accept intrusion you are potentially going to find yourself in a dangerous situation because that dog may feel inclined to guard what it feels is theirs.
We need to remember that lovely as they are dogs are predatory animals with considerable jaw strength, sharp teeth and far faster reflexes than us.
They can do severe damage if so inclined.
It is everyone’s best interests to teach our dogs that there is no need to be anxious/possessive of people around food, toys, beds etc.
Secondly, as a pp mentioned, most dog owners have little to no understanding of dog body language.
It isn’t taught in school.
It isn’t taught to new puppy owners when buying.
It isn’t taught to people adopting from a rescue.
It isn’t taught in most dog training classes.
So, while it would of course be great if everyone educated themselves that really isn’t likely to happen.
The responsibility for safety is going to fall on the dog owner and legally, the responsibility is on the dog owner aswell.
Thirdly, expecting a dog to tolerate having a toy removed or someone near its food or approaching its bed is not the same as expecting it to tolerate pestering and abuse.
There is a big difference between reacting to genuine threat/aggression like a child smacking it or bouncing on it and exhibiting possessive guarding behaviour in the absence of any real threat, like a child approaching its bed.
Presumably you wouldn’t exhibit aggression to your dog giving you ‘the eyes’ as you sit down to dinner nor would you exhibit aggression should your dog opt to sit next to you on the sofa, so why are you accepting it the other way round?