I can understand the 26 year old if you think about college and graduate and post graduate school.
If we are revitalizing the extended family with multiple generations around the daily dinner table it makes logic.
No it doesn't. Not when the rest of us are footing the bill. My kid is self sufficient and would never dream of mooching off my insurance policy. He's a man and men don't do that. My employees with family coverage saw their premiums increase by about 30% this year because other people's 26 year old parasites are still suckling at the tit!
What you don't understand is that comes at a cost for other people when you require insurance companies to do that. That is part of the problem: States have lots of Cadillac requirements on insurance companies (must cover lots of things) which makes the costs of insurance go up in those states. When the federal government does it too, it makes costs go up for everyone in every state. Let the insurance companies offer what they want and you can buy what you want. If you want to have your kid covered until 26, they will have a plan for that and you and only you will have to pay extra for it. Government mandates and regulations on insurance companies drive up health care costs, including insurance costs.