A few years ago I spent some time at a place in California where there were several orange and lemon trees. "pick and eat as many as you want" I was told. And so I did and it was great.
There was one tree though, that I was warned, produced oranges that were for marmalade, and were otherwise inedible.
"How bad can they be?" I thought, so I tried to eat one.
Pretty bad, it turns out! I could still taste the bitterness hours later.
I like marmalade, but am pretty sure that it was first made by a Scot who couldn't bear to throw away any part of something he/she had paid money for. (I am married to a scot!)