A lot of games that are heavy on resources do this and it makes sense. I'd be down for it. Heck, we should even be able to break down furniture (not craftable types) to get a default amount back.
I love this idea! Sometimes on my old file I crafted way too much and I didn't really want to go to the mystery islands just to get more materials. Plus, like others have said, some other games allowed this, so it wouldn't be bad to implement it into this one too.