For us, we dont exactly have rules about using please and thank you, but my HOH knows that I typically do say "please, thank you, yes, Sir, no, Ma'am" because of my background in martial arts. So, therefore, he knows that, for me, if I don't call someone Sir or Ma'am, I am being disrespectful. But, I think if my normal level of respect was lower, he wouldn't be concerned.
For example, there is this one boy at work who aggravates me, and sometimes I don't say Sir to him, probably because I don't have any respect for him. My HOH gets upset because he feels (and I agree) that I'm showing this person less respect that I would anyone else, and that's not nice. But at the same time, I don't say Sir to my dad, because he doesn't like that, so my HOH has no problem with me not calling him Sir.
Anyway, my point was that I don't necessarily think it is disrespectful not to say please and thank you, if that's not what you normally do.
Another comparison would be this- I have a 9 year old and a 5 year old. My 9 year old really struggles in school. She gets "good job awards" (our rewards system for the kids) when she gets Bs. My 5 year old just finished PK with top averages and perfect attendance. He gets the same rewards for higher grades. Our standard isn't the same for them.