Giving away pretty clearly means the objection is to the free nature. Getting paid makes a big difference - you now obtain tangible value from the interaction that you can turn into things like food or housing.
There's no concrete difference from the side of the gifter, between giving away time directly, giving away money earned from time spent, or giving away a tangible gift purchased with money earned from time spent. It's just more indirections.
So when someone says there's "nothing sadder", I think they should remember that the time is being given up either way. Doing so for free amounts to gifting the time. Or, flipped on its head, not chasing after the money.
People have their own reasons for making gifts. Feeling good about themselves, making someone else feel good, …. You can have your own reasons for not caring that there is no financial benefit to working extra hours on something. Maybe you enjoy the work. Maybe you are learning something. Maybe you take pride in your work and going the extra mile is rewarding in and of itself.
Unlike GP, I don't judge people who sometimes work for "free", as long as they don't have to and are aware they don't have to.
