Sheer laziness when no kids involved, there's only so much housework and cooking you can do. I highly doubt they are working their arses off cooking and cleaning all week, week in week out!
@SquirrelG
Someone sounds envious!
What a nasty post - if people don't want to work, and they don't have to, what is it to do with you what they do with their days? If they want to do nothing all day every day, how does it affect you?
This exactly! As has been said, the amount of jealousy and level of vitriol (on this thread) aimed at people who don't work is shocking. Yes if you just LURVE working, then good for you. Not everyone does. Some people are very stressed at work, and can't WAIT to leave/retire.
As a few others have said no WAY is it boring being off work/not working. It's FAR more boring being stuck on a 9 to 5 treadmill. Working for the man!
@BigWoollyJumpers
So many negative accusations. Lazy, unimaginative, boring, unproductive.
And yet, time and again, we are being encouraged to slow down, relax, take time to think, time to one-self, meditate, self care. All these things are beneficial for health and wellbeing.
If you are able, there is absolutely nothing wrong, with doing nothing.
Yeah this. ^ I am retiring next summer and I will have been working almost 45 years. Half of it full time, half part time, as WELL as raising 2 children, and like FUCK will I be volunteering for anything when I retire. 
I will be seeing friends and family, going to cinema, going on daytrips to the beach, lounging around the house doing fuck-all scoffing my fat chops with wotsits and chocolate, whilst reading trashy novels and watching crappy reality TV, going for walks, doing lunch with friends, and sunbathing outside all summer, reading That's Life and Take A Break magazine.
I have earned my stripes. Working almost 45 years AND raising 2 children, and as I said, like fuck will I be volunteering for anything because some people think anyone who has more than 5 minutes a week free time should offer their voluntary services out. Nah mate. 
IMO, most people who do volunteering do it for the company, because they're lonely. AND it's often people who have spent most of their adult life not working. I do not fall into either of those categories. (Thankfully.)