i know what you mean... but no, i don't feel guilty sleeping in, having a big night out, or watching TV.
i think it's all about balance.
if you're generally productive and you lead a pretty consistent lifestyle, then it can be healthy to "indulge" in those kinds of things every once in a while.
(sometimes you need a stimulating philosophical book.... sometimes you need 30 minutes of catty reality TV...
)
if you never did the "wrong" thing, life would probably get very boring.
i think it's important to have Sundays... those days of rest, when you can lounge around and relax - or sleep in - or stay up too late - or drink coffee - or eat dessert - or go out with friends when you should be doing your work.
if your lifestyle is perfect the other 6 days of the week, then there's no reason to feel guilty.