An interesting and creative poem about receiving something that is obviously useless. Why someone ever came up with fruitcake beats me. I like your poem about receiving it as gift. If you are going to re-gift something then you aren't suppose to eat it! LOL! I like that you brought in a part of your history stating that your grandmother may have had one.

Could this one have been the same one that your grandmother had or did this come from someone outside the family. You wrote about how re-gifting this was not your style. Is re-gifting not your style at all or is it just the fruitcake that you don't want to re-gift? I would not re-gift the fruitcake. Honestly, I would just say thank you and throw it away. It's not even a good gag gift. *Smile*

The flow of the poem does not completely work, in my opinion, because you describe eating the cake, then go to re-gifting, then go back to suffering through the cake while eating it.
Why do we think it is rude to tell someone you don't like the gift they have given you? If you do it in a polite and non-judgmental way then it should be okay.