From a discussion on the possessive noun for inani

"How would you write a book's cover then? Inanimate objects can also possess things. Have a look at that chair's wobbly leg."

True that there isn't a strict consensus on this so I'm wrong to say it's outright wrong.

But it's actually a good rule to teach - considering you can simply say "book cover" which makes "book's cover" sound awkward.

I admit "wobbly leg of the chair" is somewhat cumbersome, but in writing you could phrase it something like "He was worried the chair would not hold up on its wobbly leg" instead of "he was worried the chair's wobbly leg would not hold up". Gramma allows you to make complex sentences - but English writing tends to favor simple sentence structures.

Have a look at that chair's wobbly leg could be rewritten as have a look at that chair with the wobbly leg.