There have been a few mystery quilts over the years that have gone to charity only because I had nowhere else for them to go. I don't have a huge family that wants quilts. And, when I practice, it doesn't mean it turns out bad. If I'm sending to charity, I usually do a quicker, over all quilting as opposed to a keeper where I might do feathers or quilt each block.
I wouldn't send something shoddy, but I see nothing wrong with sending a quilt to charity that you didn't put your heart and soul into as long as it's attractive and sturdy.
Watson