Daughter 12: very much into it!
As a dad who grew up craving better graphics, I share your thoughts on “it looks a bit rubbish”. However you and I are wrong.
The gameplay and creativity it allows are amazing.
Moreover, the skills learnt incidentally by playing it are very useful. My daughter now understands servers and IP addresses. She also started developing skins for other minecraft users, so the creativity and use of software like Gimp is another skill that has come out of her minecraft usage.
Not a fan for dads (MW3!) but its one of the better bits of software for kids to learn without realising it!