Why be confused when your indoor cat occasionally scratches your furniture?
We keep them in a house to keep them safe but that means their entire world is inside however many square feet you live in…
They are cats. Scratching things is what they do. So give them lots of other acceptable options or you are just setting them up to fail. (And you’ll have to keep replacing sofas.)
Think of it like that.
*”think of it like this” (TM) is a regularly irregular purely opinion-driven piece of thought about pets and their owners pointing out the seemingly obvious*