Kalni I am a dinosaur here too! My H told me outright that he wished he could go 50/50 on custody but he knew he was not capable. I do think it is easier for them, they show up when they want to, do a few fun things, and go back to their jobs/interests. No washing the kids' clothes, cooking their meals, cleaning up after them....
But that is sad b/c I think one day they will wish they had these years back, once the kids are bigger and don't want them so much anymore....
I am frustrated for you that things are going this direction. I read every day I just don't have much in the way of advice. But you always always have my support....