I only direct your attention here because I receive a LOT of requests of for free artwork, whether it be logos, character design and sometimes even graphic novels all intended to be for free.
I'm a working professional making a living with my art. So clearly I won't be doing art for free, when it's my job to do it. BUT, I also support the idea that even artists who work freelance or even just as a hobby shouldn't work for free.
Please check out this video by Stephen Silver who explains this way better than I ever could