Yup. Ever after 5pm work thing I've been "rewarded" with is still work. Even if it's more fun than working at my desk its still work. I'm not able to do with that time what I want. It's only a reward if it is replacing work. And really it's only a reward if the amount of time that it is replacing is taken out of the sprint planning.
At the end of the day if you take a weeknight from me I'm going to be annoyed at best and upset at worst. If you take a work day from me, or part of one, but still expect me to get a full days or work done we will both be in a bad position.
I get the intention here. I used to be a people manager and I planned lots of things for after work. But I stopped when I realized how difficult it actually made things for many people and people with kids.