I think acrylic and cotton are very practical fibers because you can generally machine wash and dry them.
Unless it was something extra special (like a shawl), I would prefer not to give stuff to people that requires special washing.
For me, I don't mind soft acrylic, although the scratchy stuff is easier to knit with.
If money was no object, and caring for items was no object, of course I would choose natural fibers. But, for something cheap and easy to care for, acrylic can be a godsend.