My experience is the opposite; productivity generally feels awesome, sitting around doing nothing or wandering around the internet is generally depressing. (This is insufficient as a motivator for behavior.)
for these discussions we need to start differentiating meanings of the word "productive". When I get stuff done for an interesting task, or put together a piece of furniture, that''s being productive and usually feels pretty good. When I fill out paperwork for a lease or something, that usually feels boring and not fun, with some good feeling when it's over with. I think both of these fall under the lay definition of "productive". Leisure/fun times trades off against both of these, but my mental image when someone says "it's better to be productive than to spend time doing nothing" usually has me picturing boring homework.
If it's worth saying but not worth its own thread even in discussion it goes here.