my dog that slept in bed with me, was a show dog. So well trained I didn't even need to speak to her, just signal with my hands what I wanted her to do for me. She was very intelligent and always kept me in view and waited for my signals as to what she should do. I do understand the pack mentality. I was always the alpha female of the pack.
I don't know why others have a problem with this concept, but if you don't have it settled who is in charge before the dog ever gets near you bed, then yeah, you will have problems. But I am not that stupid. My animals know who is in charge and always have a safe place to go where no one will bother them. I feel sorry for those that have the problems with their animals trying to take over, and not respecting their people.
But we all have a relationship with those around us, be it animal or human, and what is in that relationship is up to the two in it. I personally have never had that problem with an animal, and even find their presence in my bed a comfort at times.
Over all, I think it comes down to potatoe, poetato. it is personal preference. Some like it other don't. Neither way is wrong.