Well, I do agree on some level. Half of my weekend actually go in worrying about the Monday. And other half is usually consumed in doing the leftover work that was ignored in the weekdays.
If you say that weekends are for these things only, then weekend off isn't a myth, otherwise it is.
Worrying about what do we do in weekdays is not what weekends are for. They are for living in the moment and to chill, which we often don't do. So yea, I agree with Mahatma Gandhi here.