Well I agree with you OP. It is excessive. And lazy.
I haven't got a partner at the moment, but with my last partner, it was lovely spending the weekend mornings with him, having a nice coffee, walking the dogs together, doing some exercise, and yes, doing some household chores together.
I find laziness in a man (in a person really) deeply unattractive. I can kind of forgive my teens because, well, they're teens. I wouldn't want to be with a man who spent so much time in bed - the evening is very early too!
I also think labelling you as a nag is just a horrible put down. I'd be more concerned about this and the effect on your teenagers than the sleep tbh. If all they hear is him putting you down and ignoring your needs, they will learn from example. Oh, mum's just a nag. She doesn't matter.
But, as you know, you can't change him, just yourself, so it's down to you to do something. Whether it's taking yourself off out every morning to a gym class or whatever, or leaving him, then you need to decide.