As I understand it they have very short lifespans (3-5 years) and octopus mothers only lay eggs once. They die of starvation after guarding & tending the eggs right up to hatching.

I think they just don’t have the opportunity to produce culture. Maybe they could be taught but it seems like generational learning would be extremely unlikely.

Edit: their situation has always struck me as very poetic and sad. If they are conscious their existence seems so lonely. But maybe that’s just my mammalian bias!