I have an aunt who has very little vision, so when I get a letter or card from her she uses a return address label and an address label with my name/address on it. I don't mind this, as her handwriting is quite hard to read, and I'm sure the post office appreciates being able to figure out where her letters are going. It's the same reason I don't mind her sending me preprinted cards - I know how hard it is for her to sign cards.
When I send cards or letters, I always use preprinted address labels. If the OP's DH wants handwritten return addresses, he can write them himself.