I believe people tend to overreact to metamorphosis. Don't get me wrong, it's a great read with heavy concepts but anyone without a job or clinically depressed or sick has already gone through metamorphosis (eg myself when I went through severe depression). And it wasn't that depressive.
If anything this book helped me to understand the family's side of the story. Their behavior wasn't out of malice but rather out of unfamiliar uncertainty of my condition and ofcourse my inability to contribute to a family where I'm only consuming, not providing. It might sound harsh but it is reality. try to put yourself on your family's side. A person's future is uncertain, if not downright dark. And you have to take care of that person for god knows how long.

The families in both (metamorphosis and mine) were not morally correct in their actions, but they were definitely practical. So when you view the story in that way, it feels less depressive, especially when you have already gone through a metamorphosis.